Characteristic of deep groove ball bearing:
1. Seal form: open style, Z, ZZ, RS, 2RS, 2RZ
2. Bearing stop ring: N，NR
3.Class of precision: ABEC-1,ABEC-3,ABEC-5,ABEC-7
4. Vibration rank: V1, V2. V3, V4
5. Noise rank: Z1， Z2， Z3，Z4.
6. Internal Clearance code: C0, C2, C3, C4, C5
7. Bearing material: bearing steel (9Cr18), stainless steel (AISI440C, AISI304. and AISI316), ceramics
8. Cage: stainless steel, PTFE, nylon
9. Bearing rings and ball hardness: 59 . 63HRC

Explanation:Z represents that one-side of the deep aroove bal bearina is mental dust cover, and ZZ represents that both sides are mental dust coverRS represents that one-side of the deep aroove ball bearind is non-touch sealed. and 2Rs represents that both sides are non-touchsealed
RZ represents that one-side of the deep roove bal bearing is contact seales. and 2RZ represents that both sides are contact sealed.