KAVO Handpiece Dental Bearing Stainless Steel ABEC-7 Solid SI3N4 Ceramic Balls One Ball Bearing ABEC-7 Ceramic Bearing that fits for most KAVO Dental handpiece, Stainless Steel bearing with solid SI3N4 Ceramic Balls, Bearing is made of Stainless Steel and has Solid Ceramic balls (SI3N4).