1.6201zz deep groove ball bearings

2.shield/closure:open ball bearing,Z,ZZ,RS,2RS,2RZ

3.tolerance cold:ABEC-1,ABEC-3,ABEC-5,ABEC-7

4.vibration level:V4,V3,V2,V1

5.material: bearing steel ,GCr15,carbon steel

6.retainer :PTEE,nylon,PEEK,or (stainless) steel

7.application :speed changing box,instrument,electricalmachine,home appliance,agriculture machine,ect.