Full Ceramic Bearings(The outer ring, the inner ring and balls are made of the ceramic). P0-P4, ABEC1-ABEC7, The bearings min inner: 4mm, max outer:180mm. From -196℃ To 1400℃. Full Ceramic Bearing is High-tech Product. Ceramic Parts. In acid, alkali, salt, Zirconia (ZrO2)กฏ, silicon carbide (SiC)กฏ, Silicon nitride (Si3N4)กฏ uncorrosion ability is 20, 100, 1000 times than SUS440C.