1.Precision: ABEC-3, ABEC-5, ABEC-7 2,Vibration level codes:V3, V2, V1 3. ... ,2 Metal Shield2)Tolerance codes: ABEC-1, ABEC-3, ABEC-5, ABEC-73)Vibration level codes: V4, V3, V2, V14)nternal ... .2336813652.5591853.3465100.39370.281……………………68201003.93711254.9213130.51180.6686828………………… high-quality / 6800 series / Thin-walled metric bearings