... :V4, V3, V2, V1 3.Internal clearance codes:C0,C2, C3, C4, C5 1)Shield / closure: Open,Teflon Sealed,Rubber Seals ... codes: V4, V3, V2, V14)nternal clearance codes: C0,C2, C3, C4, C55)Material: AISI52100, AISI440C, AISI304, AISI316, Ceramic6)Retainer: PTFE ... .275--R1038ZZ0.3759.5250.62515.875- high-quality& high-speed / R series / Miniature bearing