This miniature bearing is made of high quality dioxide ceramic for low noise and long service life. Miniature ball bearing is available ball bearing of small size. This miniature ball bearings has a 8mm inner diameter, a 22mm outer diameter and a 7mm thickness. Ball bearing of this size is great for work and applications that require a lot of functional mechanical parts, such as mechanical equipment, electrical instrument, toy, door and window. Ceramic bearing is impervious to and rarely require lubrication., Manufacturer: PokFhgur