1、Spring loaded design: allow gates to open and close freely by automatically adjusting height on uneven ground while eliminating gate sag. 2、Heavy duty caster: the wheel has a maximum load capacity of 110lbs and can also withstand exposure to chemicals and solvents. 3、Shock absorption: easy to move and make opening and closing gate easy. 4、Made of premium PU material and metal construction, sturdy and durable. 5、Heavy duty universal mounting plate with 6 holes to easily attach to wooden gates or along horizontal or vertical rails of a tubular farm gate. Features: Spring loaded design: allow gates to open and close freely by automatically adjusting height on uneven ground while eliminating gate sag. Heavy duty caster: the wheel has a maximum load capacity of 110lbs and can also withstand exposure to chemicals and solvents. Shock absorption: easy to move and make opening and closing gate easy. Made of premium PU material and metal construction, sturdy and durable. Heavy duty universal mounting plate with 6 holes to easily attach to wooden gates or along horizontal or vertical rails of a tubular farm gate. Specification: Material: Polyurethane (PU) + Metal Weight: Approx.1141g/ 40.2oz Caster Dia.: 50mm/ 2in Load capacity: Max.50kg/ 110bs Package List: 1 * Gate Wheel Note: Please allow slight error due to manual measurement. Thanks for your understanding.