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 absorbtion: easy to move and roll, make opening and closing gate easy. Made of premium nylon 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: Nylon + Metal Weight: Approx.1498g/ 52.8oz Caster Dia.: 100mm/ 4in Load capacity: Maximum 50kg/ 110lbs Package List: 1 x Gate Wheel Note: 1. Please allow slight error due to manual measurement. Thanks for your understanding. . 2. Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering. 3. The spring fails when the load of this product exceeds 50kg, and the maximum load is 50kg.