Miniature ball bearing is available in small size ball bearing. miniature ball bearings has an inner diameter of 8mm, an outer diameter of 22mm and a thickness of 7mm. The ball bearing of this size is ideal for precision work and applications that require many functional mechanical parts, such as mechanical equipment, electrical instruments, , doors and windows. miniature bearing is made of high quality zirconium dioxide ceramic for low noise and long service life. The ceramic bearing is impervious to corrosion and rarely requires lubrication. size: 8mm x 22mm x 7mm Material: ceramic color: White Package Contents: 16 x Bearing Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in a little different from the real thing. The measurement allowed error is +/- 1-3 cm.