Spring Loaded Design: Allows doors to open and close freely by automatically adjusting the height on uneven ground while eliminating sagging. Heavy Duty Caster: The wheel has a maximum load capacity of 220 lbs and can also withstand exposure to chemicals and solvents. Shock Absorption: Rubber gate wheel with 100kg load capacity is easy to move and roll, making it easy to open and close the gate Gate Material: Heavy duty swivel caster is made of premium PU and metal, sturdy and durable. Mounting Plate: Heavy duty universal mounting plate with 4 holes for easily attaching to wooden gates or along side horizontal or vertical rails of a tubular farm gate. Features: Materials: rubber and metal. Weight: approximately 1034 g. Diameter of the wheel. 100mm. Maximum load: 100 kg. Contents: 1 portal wheel. Note: Because measurements are taken by hand, the sizes listed may vary slightly. Thank you for your understanding. Sold by Briday Store