radial ball bearing 1621rs:1,ABEC-3,5;Z2V2,Z3V3 2,High speed 3,End cover:ZZ,RS 4,Noise level:Z1,Z2 5, ... C2,C0,C3... Lily bearing is a specialized manufacturer of radial ball bearing ... 1621rs.Features:1),Shield / closure: Open,Teflon Sealed,Rubber Seals,2 Metal Shield2),Tolerance codes: ABEC-1, ABEC-3, ABEC-5 ...