R8 Full Complement Full Ceramic Bearing 1/2" x 1-1/8" x 5/16" ZrO2 BearingR8 Full Complement Ceramic Ball Bearing 1 2" x 1 1 8" x 5 16" inch One Bearing R8 Full Complement Ceramic Ball Bearing, measures an inner diameter of 1 2", outer diameter is 1 1 8" and the width is 5 16", Bearing is made from Ceramic. R8 Ball Bearing Full Ceramic Ball Bearing Cage: No Cage Closures: Open Balls: Made from Zirconia Ceramic (ZrO) Races Material: Zirconia (ZrO) Ceramic Size: 1 2" x 1 1 8" x 5 16" inch Inner Diameter: 1 2" inch Outer