The spherical small swivel caster platform with fixed heavy-duty conveyor rollers is comfortable and practical: smart and trouble-free; the sphere can rotate 360 degrees flexibly, making it smooth to use, moving goods faster and saving time. Noiseless: The transmission unit of the roller bearing has been polished during the production process, and the surface is smooth, and no loud noise will be produced during transportation. The entire universal ball rolls smoothly and quietly through the drive of ball bearings. Wide range of applications: Ball roller bearings mainly help people move goods, not only in homes such as sofas, display cabinets, carts, shelves, scooters, cabinets and kitchen appliances, but also in transmission systems, power systems, processing systems, packaging machines, etc. Industrial and Auxiliary Machinery. Ball material: nylon Package includes: 1 piece/4 pieces ball caster (according to your choice) Note: 1. Due to different monitors and lighting effects, the actual color of the item may be slightly different from the color shown in the picture. 2. Please allow 1-3cm error due to manual measurement. (1 inch = 2.54 cm) Thanks for your support :)