Spring-loaded design allows gates to open and close freely by automatically adjusting the height on uneven ground. High load capacity, size (approx.): 10.2 cm - 272 kg. Made of rubber and metal, more sturdy and durable, not easy to break. Universal mounting plate with holes for easy alignment of horizontal or vertical rails of a gate. Contents: 1 door roller, 3 screws, 3 nuts, 3 washers. Allows gates to open and close freely by automatically adjusting the height on uneven ground. High load capacity and can also withstand exposure to chemicals and solvents. The rubber gate wheel with brake is easy to move and roll, making it easy to open and close the gate. Material: Rubber + Metal. Color: Silver, Black. Approximate dimensions: 10.2 cm - 272 kg. Contents: 1 gate roller, 3 screws, 3 nuts, 3 pucks. Due to lighting and monitor settings, the color of the item may vary slightly from that shown in photos. Due to hand measurement, measurements shown may vary by 0.5-2 cm.