Miniature bearings specifications: 1) Shield / closure: Open bearing, Z, ZZ, RS, 2RS 2) Snap ring: N, NR 3) Tolerance codes: ABEC-1, ABEC-3, ABEC-5, ABEC-7 4) Vibration level codes: V4, V3, V2, V1 5) Internal clearance codes: C2, C3, C4, C5 6) Material: Gcr15, carbon steel, stainless steel 7) Bore size: 1 - 20mm