XIANQI 4 Inch Heavy Duty Rubber Mute Spring Loaded Gate Door Wheel Caster Spring Wheel Home Gate Door Roller Material: Metal and rubber. 4 inch Gate Caster with Adjustable Spring Bracket is designed to allow gates to open and close freely. ; It features a 50-60kg load rating and a spring-loaded clamp that acts as a when the caster is rolling over rough or uneven surfaces. ; It also features a universal mount for wood or metal gates. Heavy Duty spring-loaded gate casters adjust with surrounding terrain to maintain gate height throughout the opening and closing cycles. ; These rotating supports work equally well on level and uneven exterior surfaces such as asphalt, brick, concrete, dirt, grass, gravel and pavers. Colour: Black Size: 10cm Delivery Quantity: 1 Piece