Product InformationMade of iron, sturdy, durable, high strength, good stability, low creep. Good wear resistance and chemical stability, can be used for a long time. Product Advantages Double bearings together with its structure can ensure the stability and smoothness when the door is rolling. Reduce vibration, reduce noise and ensure smooth operation. Ideal for internal or external use. Widely UsedUsage: Spare Parts, Gate Wheels, Sliding Fence, Sliding Window Bearings, 3D Printer, Shower Screen Bearings, Can Washer, Dog Door, Garden Gates, Wire Rope Guides , etc.Suitable for professional (industrial context) or as a handyman. Easy to useEasy to install and use. For experienced and non-expert users. Wheel diameter is 15mm, wheel overall height is 28mm, U-groove depth is 4mm. The groove in the shape ofU can fit the reverse track perfectly. Notes for use Maximum load capacity 40 kg. Iron as main material, do not use in humid environment.