... : Open, Z, ZZ, RZ,2RZ,RS, 2RS 2) Quality level: reach the same level as the Japanese and European bearings 3) Tolerance ... -1 (P0), ABEC-3 (P6),ABEC-5(P5)4) Noise Level: EMQ V1 Z2, EMQ V2 Z3, EMQ V3 Z4, EMQ ... 8 4 2 inner ring Deep Groove Ball Bearings 6000 series