Material: The swivel casters are wheels made of soft rubber and TPE materials, ultra quiet, will not disturb anyone during work, high elasticity, 360 flexible use. Bearing Design: Ball bearing, built-in bearing, steel ball steering design, sealed bearing has low friction resistance, flexible rolling, can rotate 360 degrees, stable, high temperature resistance, high speed, dustproof and non-stick, and can be used for a long time. Built-in silent bearing, very quiet and durable. It is the ideal choice for all DIY furniture with mobile casters. Specifications: Drum diameter: 25mm / wheel width of each drum: 13mm / threaded screw height: 15mm / total height: 54mm, compact in shape, including 4 casters with M6 threaded screw, and easy to install. Suitable for a variety of floors: Made of soft rubber, which is soft and will not damage the floor. Rubber casters have elasticity, toughness and durability. Suitable for all types of floors, such as ceramic tiles, cement floors, marble, carpets, wooden floors, etc. Wide range of uses: Furniture casters are very suitable for indoor or outdoor use. Mobile casters can be used in homes, lawns, factories, shops, companies and hospitals. Swivel casters ideal for furniture and other small mobile furniture (such as coffee tables, desks, bookshelves, shoe cabinets, shopping carts, transport trolleys).