This miniature bearing is made of high quality dioxide ceramic for low noise and long service life. 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. 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. Ceramic bearing is impervious to and rarely require lubrication., Manufacturer: CTRLZS