Function:Material: This U-slot wheel is made of high quality galvanized steel, sturdy and durable, waterproof and anti-corrosion.Dimensions : wheel diameter 50mm, wheel inner width 22mm, outer width 30mm. Suitable for 19mm round pipe rail (please confirm the pipe rail size before ordering)Loading capacity: 3mm thick bracket, which can easily carry heavy doorsBall bearing: double roller bearing, smooth sliding, easy to push the door Suitable for: front doors, factory doors, sliding fences, dog gates, reverse rails, industrial machinery, roller shutters, container shelves These sliding door wheels are made of high quality steel Galvanized coating , strong, durable, waterproof and anti-corrosion. They are perfect used for reversing tracks, industrial machinery, rolling doors, sliding doors, factory doors, inspection doors, dog doors, container shelves. Specification: Material: Galvanized Steel Wheel Diameter: 50 mmInner wheel width: 30 mmExternal width of the wheel: 22 mm Frame size: 68 x 38 mm (length x width) Bolt hole distance: 47 x 18 mm (L x W) Bracket thickness: 3mmPackage Contents:2 U-Groove Gate WheelPackage Include: 50mm Sliding Gate Wheels, U-Groove Steel Wheels, Reverse Track U-Groove Wheel, Machine Industrial 2pcsMain points:1. The product size is manually measured, there may be errors2. Since different monitors display different colors, please refer to the actual color you received.3.Please confirm the size before purchasing.Note: the Data is manual measurement, please allow 1-99cm error, due to differences between light and screen, there will be a certain color difference, the specific received in kind prevail.>