Specifications:Made of premium quality manganese steel material, it is safe and durable for you to use.This swivel caster is featured with special spring-loaded deign, so it allows the gate to open and close the gate freely by automatically adjusting the height on uneven ground while eliminating the gate sagging.It can be widely used in home and office equipment, communication equipment, ship assembly and other machinery industries.Item Name: Spring WheelMaterial: Manganese SteelFeatures: Spring-loaded Design, Fine Workmanship, DurableSize: 30cm x 11cm x 7cm/11.81" x 4.33" x 2.76" (Approx.)Wheel Diameter: 63mm/2.48" (Approx.)Wheel Width: 32mm/1.26" (Approx.)Installation Height: 273mm/10.75" (Approx.)Notes:Due to the light and screen setting difference, the item& 39;s color may be slightly different from the pictures.Please allow slight dimension difference due to different manual measurement.Package Includes:1 x Spring Wheel