1,ABEC-3,5,7;Z2V2,Z3V3 2,High speed 3,End cover:ZZ,RS 4,Noise level:Z1,Z2 Z3 5,C2,C0,C3... Features ... / closure: Open,Teflon Sealed,Rubber Seals,2 Metal Shield2),Tolerance codes: ABEC-1, ABEC-3, ABEC-5, ABEC-73),Vibration level codes: V4 ... : PTFE, Nylon, PEEK Or Stainless Steel7),Bore Size:from 3mm to 10mm8),Outside Diameter:from 6mm ...