... :1mm-12mm 2.Stainless steel:AISI440C, AISI304, AISI316 3.ABEC-1 ABEC-3 ABEC-5,ABEC-7 4Noise level:Z1,Z2,Z3,Z4 High Performance ... as the Japanese and European bearings3.Tolerance level:ABEC-1(P0),ABEC-3(P6),ABEC-5(P5),ABEC-7(P4)4.Noise Level:EMQ V1 ... P4;C0,C2,C3,C4,C5AFBMA STD.20-1987:ABEC-1 ABEC-3 ABEC-5 ABEC-7Noise level:Z1,Z2,Z3,Z4Vibration level:V1,V2 ...