1.Precision: ABEC-3, ABEC-5, ABEC-7 2,Vibration level codes:V4, V3, V2, V1 3.Internal ... clearance codes:C0,C2, C3, C4, C5 1)Shield / ... closure: Open,Teflon Sealed,Rubber Seals,2 Metal Shield2)Tolerance codes: ABEC-1, ABEC-3, ABEC-5 ... --R1038ZZ0.3759.5250.62515.875- high-quality& high-speed / R series / Miniature bearing