MATERIAL: Made of high quality galvanized steel, sturdy, durable, waterproof and anti-corrosion SIZE: Wheel diameter is 50mm, interior width of the wheel is 22mm, exterior width is 30mm. Fits 19mm round tube track (Please confirm your tube track size before ordering) LOAD CAPACITY: With 3mm thick bracket, each U-groove gate wheel supports up to 300kg, capable of handling heavy duty gates ROLL BEARING: Double roll bearings ensure stable and smooth sliding operation, making it easy to open and close the gate GREAT FOR: Inverted track systems, industrial machinery, rolling gates, sliding doors, factory gates, driveway gates, dog gates, container shelves Specifications: Material: Galvanized Steel Wheel Diameter: 50mm Interior Width of Wheel: 22mm Exterior Width of Wheel: 30mm Bracket Size: 68 x 38mm (L x W) Bolt Hole Distance: 47 x 18mm (L x W) Bracket Thickness: 3mm Loading Capacity: 300kg Package Includes: 2 U-Groove Gate Wheels