... cover:ZZ. 4,Noise level:Z1,Z2. 5,C2,C0,C3. high Performance ceramic ball bearing-china bearingWe have ... ceramic bearing, hybrid ceramic bearing and full ceramic bearing, the hybrid ceramic bearing has steel inner and outer rings with ceramic balls, as for the full ceramic ... than steel, that makes ceramic bearing go faster with lower heat generated.full ceramic Si3N4 ZrO2 Full Complement Thrusthybrid ...