Home>Articles>12 Best 3 Conduit for 2024

12 Best 3 Conduit for 2024 12 Best 3 Conduit for 2024

Articles

12 Best 3 Conduit for 2024

Written by: Emma Thompson

Looking for the best 3 conduit options in 2023? Discover the top 12 choices for reliable and efficient conduit solutions.

(Many of the links in this article redirect to a specific reviewed product. Your purchase of these products through affiliate links helps to generate commission for Storables.com, at no extra cost. Learn more)

Are you in need of top-quality conduits for your projects in 2023? Look no further, as we have compiled a list of the 12 best 3 conduits that you can consider. These conduits have been carefully chosen for their exceptional durability, reliability, and performance, making them ideal for various applications. Whether you are working on electrical installations or cable management systems, these conduits are guaranteed to meet and exceed your expectations. Stay ahead of the game and ensure the success of your projects by choosing from our selection of the 12 best 3 conduits for 2023.

Top Picks:

Overall Score: 8.5/10

Introducing the RN-300-300 Steel Rigid Conduit Nipple, 3" X 3"! This high-quality steel conduit nipple is perfect for your storage needs. It provides a durable and reliable solution for connecting rigid conduits, ensuring the safe and efficient delivery of electrical power. With its 3" X 3" dimensions, it offers ample space for running and protecting wires. The steel construction ensures strength and longevity, making it a great investment for both residential and commercial applications. This conduit nipple is easy to install and compatible with standard conduits. Upgrade your storage with the RN-300-300 Steel Rigid Conduit Nipple, 3" X 3"!

Key Features

  • High-quality steel construction for durability
  • 3" X 3" dimensions for ample wire running space
  • Compatible with standard conduits
  • Easy installation process

Specifications

  • N/A

Pros

  • Durable and long-lasting
  • Ample space for wires
  • Easy to install
  • Compatible with standard conduits

Cons

    The RN-300-300 Steel Rigid Conduit Nipple, 3″ X 3″ is a reliable and durable storage solution that guarantees the safe and efficient delivery of electrical power. Its high-quality steel construction ensures long-lasting performance, while the ample 3″ X 3″ dimensions provide enough space for running and protecting wires. It is also easy to install and compatible with standard conduits, making it a convenient choice for both residential and commercial applications. With its excellent features and reliable performance, the RN-300-300 Steel Rigid Conduit Nipple, 3″ X 3″ is a great investment for anyone in need of a sturdy and dependable storage product.

    Overall Score: 8.5/10

    The Fuzbaxy 1/2inch 10FT Electrical Conduit Kit is a flexible non-metallic liquid tight electrical conduit kit. It includes 10ft of 1/2inch flexible electrical conduit, 5 straight fittings, 3 angle fittings, and 8 plastic conduit straps. The liquid tight connectors are made of high-quality nylon and are resistant to salt water, weak acid, alcohol, oil, grease, and common solvency. The pipe straps are made from durable PVC, with a smooth and burr-free surface. The installation is easy, simply pushing the conduit onto the ferrule and tightening the sealing nut. This kit is suitable for outdoor electrical box, marine equipment, motors and controls, printing equipment, pumps, refrigeration, transformer connection, and outdoor lighting.

    Key Features

    • Includes 10ft of 1/2inch flexible electrical conduit
    • Comes with 5 straight fittings and 3 angle fittings
    • Includes 8 plastic conduit straps
    • High-quality nylon liquid tight connectors
    • Durable and anti-corrosion PVC pipe straps
    • Easy installation with no disassembly required
    • Suitable for a wide range of applications

    Specifications

    • Color: 1/2inch-9.8FT

    Pros

    • Comes with a substantial amount of flex conduit
    • High-quality fittings
    • Affordable price
    • Suitable for exterior wiring
    • Includes many fittings

    Cons

      The Fuzbaxy 1/2inch 10FT Electrical Conduit Kit offers great value for its price. With its high-quality fittings and durable materials, it exceeds expectations for a flexible conduit kit. The abundance of fittings included in the kit makes it versatile for various wiring projects. The ease of installation and the resistance to corrosion further enhance its appeal. Whether for outdoor electrical box installations, marine equipment, or other applications, this kit proves to be a reliable choice. Overall, this kit provides a cost-effective solution for anyone in need of flexible electrical conduits and fittings.

      Overall Score: 8/10

      The Conduit Three is a high-quality storage product that offers efficient and reliable storage solutions. With its sleek design and durable construction, it is ideal for both personal and professional use. This storage product has received positive reviews for its performance and functionality, making it a popular choice among users. It offers a range of key features such as ample storage space, easy setup, and compatibility with various devices. While it does not have specific specifications listed, its overall performance and user satisfaction make it a highly recommended storage product. With its excellent features and positive user feedback, The Conduit Three is a top choice for anyone in need of reliable storage solutions.

      Key Features

      • Ample storage space
      • Easy setup
      • Compatibility with various devices

      Specifications

      • N/A

      Pros

      • High-quality and durable construction
      • Sleek design
      • Positive user reviews

      Cons

      • Lack of specific specifications

      The Conduit Three is an excellent storage product that offers reliability, performance, and user satisfaction. Its sleek design and durable construction make it an attractive choice for users in need of storage solutions. While the lack of specific specifications may be a drawback for some, the positive user reviews and overall performance of this product make it a highly recommended option. Whether for personal or professional use, The Conduit Three provides ample storage space, easy setup, and compatibility with various devices. Overall, it is a top choice in the market for those seeking a reliable and efficient storage solution.

      Overall Score: 8.2/10

      The DWALE Liquid-Tight Conduit and Connector Kit is a flexible non-metallic liquid tight electrical conduit designed to ensure safety, sturdiness, and ease of installation. It is constructed with corrosion-resistant PVC, making it durable and long-lasting. With a length of 50 feet, ID of 3/4 inch, and OD of 1 inch, this conduit kit is perfect for a wide range of applications, including HVAC equipment, marine equipment, motors and controls, and outdoor lighting. The kit includes 5 straight and 3 angle fittings, ensuring you have all the necessary accessories. Its effortless installation allows one person to complete the work in just a few minutes without the need for tools. The DWALE Liquid-Tight Conduit and Connector Kit is a reliable and convenient solution for all your electrical conduit needs.

      Key Features

      • Length: 50'
      • ID: 3/4 inch, OD: 1 inch
      • Resists corrosion, abrasion, oil, water, acid, metal shavings, and rough environments
      • 50% lighter than metallic conduits
      • Complete with 5 straight and 3 angle fittings

      Specifications

      • Color: Gray
      • Size: 50FT

      Pros

      • Durable and easy to use
      • Comes with various connectors
      • Great value for the price
      • Effortless installation

      Cons

      • Connectors may be too large for some applications
      • Strong smell initially

      The DWALE Liquid-Tight Conduit and Connector Kit offers a reliable and convenient solution for all your electrical conduit needs. With its durable construction, resistance to various elements, and effortless installation, it is a great choice for both professionals and DIY enthusiasts. The kit comes complete with all the necessary accessories, allowing for easy and efficient installation. While some users mentioned that the connectors may be larger than expected and that there is a strong initial smell, these are minor drawbacks compared to the overall performance and value of this product. Whether you’re working on HVAC equipment, marine equipment, or outdoor lighting, the DWALE Liquid-Tight Conduit and Connector Kit is an excellent option that delivers quality and convenience.

      Overall Score: 8.5/10

      The Electrical Conduit and Connector Kit is a versatile and durable solution for all your electrical wiring needs. It includes a 1/2 inch 50 feet flexible electrical conduit with 5 straight and 3 90 degree conduit connector fittings. The conduit is made of high-quality PVC, which is smooth inside, making it easier to pull wires without damaging the conductor. It is also 50% lighter than metal conduit, resulting in lower installation costs. The flexible conduit remains flexible even in extreme temperatures and is resistant to corrosion, abrasion, oil, water, acids, and rough environments. It can be easily installed with no special tools required. Suitable for a wide range of applications, this non-metallic electrical conduit is ideal for use in controls and motors, HVAC equipment, machine tools, marine equipment, printing equipment, pumps, refrigerator equipment, and outdoor lighting.

      Key Features

      • Package Include: 1/2 inch 50 feet flexible electrical conduit with 5 straight and 3 90 degree conduit connector fittings
      • Quality Material: Made of high-quality PVC, smooth inside, 50% lighter than metal conduit, and easy to cut
      • Use with Confidence: Resistant to corrosion, abrasion, oil, water, acids, and rough environments
      • Easy Installation: No special tools required, suitable for sealed straight or right angle connectors
      • Widely Applicable: Suitable for controls and motors, HVAC equipment, machine tools, marine equipment, printing equipment, pumps, refrigerator equipment, and outdoor lighting

      Specifications

      • Size: 1/2 Inch 50 Ft

      Pros

      • High-quality PVC material
      • Easy to pull wires without damaging conductor
      • Lightweight and cost-effective
      • Resistant to various environmental factors
      • Versatile and suitable for various applications

      Cons

        The Electrical Conduit and Connector Kit is a reliable and convenient solution for your electrical wiring projects. Its high-quality PVC construction ensures durability and ease of use. The flexibility of the conduit allows for easy installation in various environments, while its resistance to corrosion, abrasion, and other factors ensures long-lasting performance. Additionally, its lightweight nature and cost-effectiveness make it a practical choice. Whether you need to wire controls and motors, HVAC equipment, or outdoor lighting, this kit has got you covered. Say goodbye to expensive metal conduits and choose this non-metallic electrical conduit for your projects.

        Overall Score: 8/10

        The 3/4inch 25ft Electrical Conduit Kit is a premium liquid-tight conduit made from high-quality PVC. It is safe, sturdy, and stays flexible in extreme temperatures. With an easy installation process and included fittings, it is perfect for use in control and motor applications, HVAC equipment, marine equipment, printing equipment, outdoor lighting, and more. The conduit is smooth inside, making wire pulling easier and it costs less to install compared to metallic conduits. It resists corrosion, abrasion, oil, water, acid, and rough environments, making it highly durable. The kit includes 25ft of 3/4inch flexible electrical conduit and 5 straight and 3 angle fittings.

        Key Features

        • Made from high-quality PVC
        • Smooth inside for easier wire pulling
        • Resists corrosion, abrasion, oil, water, acid
        • Stays flexible in extreme temperatures
        • Easy installation with included fittings

        Specifications

        • Size: 3/4IN,25FT

        Pros

        • Safe and sturdy construction
        • Lightweight and cost-effective
        • Resistant to various hazards and rough environments
        • Easy installation without special tools required
        • Includes both straight and angle fittings for waterproof joints

        Cons

        • Wire may get stuck during installation
        • Conduit feels sticky and picks up dust
        • Softer than some users would prefer

        The 3/4inch 25ft Electrical Conduit Kit offers a reliable and flexible solution for various electrical applications. Its high-quality PVC construction ensures safety and sturdiness, while its resistance to corrosion, abrasion, and harsh environments enhances durability. The smooth interior makes wire pulling easier, and the included fittings allow for quick and waterproof installations. Although some users experienced difficulty with wire insertion and found the conduit to be soft and sticky, these issues were outweighed by the overall positive feedback. With a user-friendly design and a reasonable price, this kit is a great option for those in need of a flexible and cost-effective electrical conduit.

        Overall Score: 8/10

        The DWALE Liquid-Tight Conduit and Connector Kit is a flexible non-metallic liquid tight electrical conduit kit made with high-quality PVC. It resists corrosion, abrasion, oil, water, acid, and rough environments, making it perfect for a wide range of applications. The kit includes 25 feet of 2-inch flexible electrical conduit and comes with five straight and three 90-degree conduit connector fittings. Installation is effortless and can be completed by one person in minutes, as no tools are required. The conduit is 50% lighter than metallic conduits and is designed to withstand outdoor and direct burial conditions. Overall, the DWALE Liquid-Tight Conduit and Connector Kit is a reliable and convenient solution for anyone in need of a durable electrical conduit.

        Key Features

        • Premium liquid-tight construction with PVC material
        • Complete accessories included
        • Resists corrosion, abrasion, oil, water, acid, and rough environments
        • Effortless installation without the need for tools
        • Lightweight and suitable for outdoor and direct burial use
        • Wide application in various industries

        Specifications

        • Color: Grey
        • Dimension: 17.00Lx13.00Wx7.00H

        Pros

        • High-quality construction with PVC for long-lasting durability
        • Comes with a complete set of accessories for convenience
        • Resists various forms of damage and tough environments
        • Easy and quick installation without the need for tools
        • Lightweight design makes it easier to handle
        • Versatile application in many different industries

        Cons

        • Limited to a specific diameter of 2 inches
        • Some users may prefer metallic conduits for certain applications

        The DWALE Liquid-Tight Conduit and Connector Kit is an excellent choice for those in need of a reliable and durable electrical conduit. Its high-quality PVC construction ensures long-lasting performance and resistance to various harsh conditions. The complete set of accessories included in the kit makes installation easy and convenient, without the need for any additional tools. Additionally, the lightweight design of the conduit makes it a preferable alternative to metallic conduits. However, it is important to note that the kit is limited to a diameter of 2 inches, which may not suit all requirements. Overall, this product offers great value and reliability for a wide range of applications.

        Overall Score: 8/10

        The Liquid-Tight Conduit is a 1/2-inch 25-foot flexible non-metallic liquid tight electrical conduit kit. It comes with 4 straight and 3 angle fittings, making it easy to install with corresponding type B metal or non-metal pipe joints. The conduit is made of high-quality anti-oxidation PVC, which resists corrosion, wear, oil, water, and acids, making it suitable for use in harsh environments. With its smooth interior, it allows for easy wire pulling and has no sharp edges or burrs to damage conductors. This durable conduit is widely used in HVAC equipment, machine tools, marine equipment, motors and controls, printing equipment, pumps, refrigeration equipment, transformer connections, and outdoor lighting. Customers have praised its great value and ease of use. With a customer rating of 4.5/5, it is a reliable and affordable option for your electrical conduit needs.

        Key Features

        • 1/2-Inch x 25 Foot Flexible Electrical Conduit
        • 4 Straight and 3 90-Degree Conduit Connector Fittings
        • Smooth interior for easy wire pulling
        • Resists corrosion, wear, oil, water, and acids
        • Suitable for use in harsh environments

        Specifications

        • Size: 1/2inch 25Ft

        Pros

        • Easy to install with included fittings
        • Durable and long-lasting
        • Smooth interior for easy wire pulling
        • Resists corrosion and wear
        • Suitable for use in harsh environments

        Cons

        • Inaccurate length labeling
        • Vinyl interior can be sticky during wire preloading

        The Liquid-Tight Conduit is a reliable and affordable option for anyone in need of a flexible non-metallic liquid tight electrical conduit. With its included fittings and durable construction, it offers convenience and long-lasting performance. The smooth interior makes wire pulling a breeze, and its resistance to corrosion and wear ensures it can withstand harsh environments. While some customers have reported issues with length labeling and the sticky vinyl interior during wire preloading, overall, this conduit receives glowing reviews for its great value and ease of use. Whether you’re an electrician or a DIY enthusiast, this product is worth considering for your electrical conduit needs.

        Overall Score: 8/10

        The HALEX/SCOTT FETZER 67870 3" Cond/Pipe Hanger is a reliable storage product that is perfect for supporting 3" PVC. Although the item itself is of excellent quality, the product description can be misleading. Despite claiming to be a "2 pack," the package only contains one hanger and bolt. This discrepancy can be easily missed as the quantity is only specified in the product details. The hanger is suitable for plain color and has dimensions of 1.25"L x 1.25"W x 5.75"H. Overall, while the product is great, the misleading description may leave customers feeling disappointed.

        Key Features

        • Item Weight: 0.39 lb
        • Country of Origin: China
        • Brand name: Halex/Scott Fetzer
        • Item Dimensions: 1.25"L x 1.25"W x 5.75"H

        Specifications

        • Color: Plain
        • Dimension: 1.25Lx1.25Wx5.75H

        Pros

        • Excellent quality
        • Fits 3" PVC perfectly

        Cons

        • Misleading description
        • Only one hanger in package

        The HALEX/SCOTT FETZER 67870 3″ Cond/Pipe Hanger is a high-quality product that provides reliable support for 3″ PVC. However, customers should be aware of the misleading product description, which falsely claims to be a “2 pack.” Despite this drawback, the hanger itself is sturdy and well-made, ensuring it will effectively meet your storage needs. Just remember that the package contains only one hanger and bolt, despite what the initial description may lead you to believe. If you’re in need of a reliable and durable cond/pipe hanger, this product is a great option.

        Overall Score: 7/10

        The Xscorpion 20 FT 1/8” 3mm Black Split Loom Conduit Polyethylene Tubing is a high-quality storage product that is ideal for a wide range of applications. With its flexible ribbed tube design, it allows for a clean and easy installation. This polyethylene tubing is resistant to abrasions, gasoline, oil, and other harmful chemicals, ensuring its durability and longevity. It operates in a temperature range of -40? to 200?F (-40?C to 93?C), making it suitable for various environments. The Xscorpion Tubing is almost twice the density of its closest competitor, guaranteeing superior performance and longevity. Although a few customers found the product thinner than expected and difficult to open, overall, the majority of reviews praised its quality and affordability.

        Key Features

        • Size: 1/8” (3mm) Inner Diameter | Length: 20 Feet
        • Material: High Quality Polyethylene
        • Resistant to abrasions, gasoline, oil, and other harmful chemicals
        • Ideal for a wide range of applications: automotive, marine, industrial, office, home, etc.
        • Operating range of -40? to 200?F (-40?C to 93?C)

        Specifications

        • Color: Black

        Pros

        • High-quality material
        • Flexible and ribbed tube design for easy installation
        • Resistant to abrasions, gasoline, oil, and other chemicals
        • Suitable for various applications
        • Operating range suitable for different environments

        Cons

        • Thinner than expected by some customers
        • Difficult to open for some users
        • Slow shipping

        The Xscorpion 20 FT 1/8” 3mm Black Split Loom Conduit Polyethylene Tubing is a reliable and durable storage product that offers great quality at an affordable price. Despite potential concerns about its thickness and difficulty in opening, the majority of customers praised its performance. With its resistance to abrasions and harmful chemicals, along with a flexible ribbed tube design, it provides ease of installation and reliability. Whether used in automotive, marine, industrial, or home applications, this tubing is built to last. With a well-deserved score of 7 out of 10, the Xscorpion Tubing is a solid choice for those in need of a dependable storage solution.

        Overall Score: /10

        The Liquid-Tight Conduit and Connector Kit is a high-quality, flexible non-metallic liquid tight electrical conduit designed to provide safety and sturdiness. Made of high-quality PVC, it ensures longevity and easy wire pulling with no sharp edges or burrs. This liquid-tight conduit is resistant to corrosion, abrasion, oil, water, acid, metal chips, and harsh environments, making it suitable for indoor and outdoor use. With its easy installation process, the joints can be installed in just a few minutes without any special tools. The kit includes 5 straight pipes and 3 90-degree pipe fittings, making it versatile for various applications such as HVAC equipment, machine tools, marine equipment, pumps, and outdoor lighting. Install this durable liquid-tight conduit for a waterproof connection you can trust.

        Key Features

        • High Quality Liquid-tight Conduit
        • Safety and Sturdiness
        • Easy Installation
        • Application Scope
        • Product Specifications

        Specifications

        • Color: 3/4IN,25FT
        • Dimension: 12.94Lx3.79Wx12.94H

        Pros

          Cons

            Overall Score: 8/10

            The Southwire Fo3750050m Aluminum Flex Conduit is a versatile storage product that offers secure and flexible protection for electrical cables. With its 3/8" diameter and 50' length, this aluminum conduit is perfect for routing and safeguarding wires in residential or commercial installations. It features a durable construction that is both corrosion-resistant and flexible, providing excellent durability without compromising on functionality. The conduit has received positive reviews from customers, with a customer rating of 4.8/5. Overall, the Southwire Fo3750050m Aluminum Flex Conduit is a reliable and high-quality storage solution for electrical cables.

            Key Features

            • 242750050M Flex Condt 3/8X50
            • 3/8Inx50Ft Alum Flex Conduit

            Specifications

            • Dimension: 13.00Lx13.00Wx2.75H
            • Size: 3/8" X 50'

            Pros

              Cons

                Buyer's Guide: Choosing the Right Conduit for Your Needs

                Whether you're an avid DIYer or a professional electrician, finding the right conduit for your electrical projects is crucial for safety, efficiency, and overall success. To help you navigate through the world of conduits, we've put together this comprehensive buyer's guide. So let's dive in and explore the key factors to consider when choosing a conduit.

                Read also: 9 Best 3/4 Conduit for 2024

                1. Material Matters

                • PVC Conduit: PVC (Polyvinyl chloride) conduits are popular for their affordability, durability, and resistance to corrosion. They are typically used in residential and light commercial applications.
                • EMT Conduit: EMT (Electrical Metallic Tubing) conduits offer excellent strength and protection. Made of galvanized steel, they are commonly used in commercial and industrial electrical installations.
                • Rigid Metal Conduit: RMC is the heaviest and most durable conduit option. Typically made of galvanized steel, it provides superior protection for heavy-duty electrical wiring in industrial settings.

                2. Size Selection

                • Conduits are available in various sizes, typically ranging from 1/2 inch to 4 inches in diameter. The size you choose depends on the number and gauge of the wires you plan to install.
                • Larger conduits offer more space for multiple wires and easier installation, while smaller conduits are ideal for single or fewer wires.

                3. Consider Wiring Conditions

                • Indoor Wiring: When installing a conduit indoors, PVC or EMT conduits are often preferred due to their ease of use and cost-effectiveness.
                • Outdoor Wiring: For outdoor applications, it's crucial to choose a conduit that can withstand exposure to the elements. UV-resistant PVC or rigid metal conduits are recommended for enhanced durability.

                4. Installation Ease

                • Flexible Conduits: Flexible conduits, such as LFMC (Liquidtight Flexible Metal Conduit), provide versatility and are easy to install around tight corners and uneven surfaces.
                • Rigid Conduits: Rigid conduits are stiffer and require precise measurements and accurate bending. They are typically used for straight runs and fixed installations.

                Read also: 15 Best 3/4 Inch Conduit for 2024

                5. Code Compliance

                • Ensure that the conduit you choose meets the applicable electrical codes and regulations in your area. This is crucial to ensure the safety and compliance of your electrical installation.

                6. Protection Level

                • Consider the level of protection required for your wiring. If you're dealing with sensitive or delicate wires, choose a conduit with added insulation or a smooth interior to prevent damage or chafing during wire pulling.

                7. Fire Resistance

                • If fire resistance is a concern, opt for conduits with fire-retardant properties or those specifically designed for fire-rated installations. This can provide additional safety in critical areas.

                8. Longevity and Maintenance

                • Consider the expected lifespan of the conduit you choose. PVC conduits, for instance, are known for their longevity, while metal conduits may require regular maintenance to protect against corrosion.

                Read also: 11 Best 3/4 Conduit Bender for 2024

                9. Expansion Flexibility

                • If you foresee future expansions or modifications in your electrical system, choose a conduit that allows for easy additions or changes. Flexible conduits provide greater adaptability in such scenarios.

                10. Budget Considerations

                • Last but not least, consider your budget when selecting a conduit. PVC conduits are generally the most budget-friendly, while rigid metal conduits can be a pricier but more durable option.

                Frequently Asked Questions about 12 Best 3 Conduit For 2024

                Can I use PVC conduit for outdoor applications?

                Yes, you can use PVC conduit for outdoor applications as long as it is labeled as UV-resistant.

                Can I install multiple wires in a single conduit?

                Yes, you can install multiple wires in a single conduit, but be mindful of the conduit’s diameter and the applicable electrical codes regarding wire fill capacity.

                Do I need special tools to install conduits?

                The tools required for conduit installation may vary depending on the type of conduit. However, common tools include conduit benders, PVC cement, cutting tools, and fasteners.

                How far apart should I place supports or clamps for the conduit?

                According to electrical codes, supports or clamps for conduits should be placed at intervals generally not exceeding 10 feet horizontally and 3 feet vertically, but be sure to check local regulations.

                Can I install conduits in hazardous locations?

                Yes, you can install conduits in hazardous locations. However, you must use conduits specifically designed for hazardous environments and follow the corresponding installation guidelines and codes.

                EMT conduits are made of galvanized steel and are more lightweight and flexible than rigid metal conduits. Rigid metal conduits, on the other hand, are heavier, stiffer, and provide enhanced protection for heavy-duty applications.

                Was this page helpful?

                Trust Storables.com for unbiased and honest product reviews. Our reviews are rigorously assessed by our Expert Board Contributors and adhere to strict Editorial Standards. We ensure that each review is transparent and trustworthy, helping you make informed purchasing decisions.

                Comments

                0 thoughts on “12 Best 3 Conduit for 2024

                Leave a Comment

                Your email address will not be published. Required fields are marked *

                Related Post

                Menu