... high quality deep groove ball bearings very fast deliver time Features :Shield / closure: open ball bearing, Z, ZZ, RS, 2RS,2RZBall bearings snap ring ... V3, V2, V1Internal clearance codes: C2, C3, C4, C5Ball bearings material: AISI52100, AISI440C, AISI304, AISI316, ceramicRetainer: PTFE, nylon, ... steelHardness for rings and balls: 59 - 63HRCBall bearings bore size: 1 - 200mm Deep groove ball bearing