self -aliging ball bearings 1,high quality 2, long life and low price 3, prompt delivery Self-aliging ball bearingsSeal form: open style, Z, ZZ, RS, 2RS ... AISI316), ceramics. Keeper: stainless steel, PTFE, nylon. Bearing ferrule and ball hardness:, 59 - 63 HRC.... Bearing No.Principal dimensions (mm)Limiting ... .513.20.7200121260110221.54500560023.215.50.9000and more .... self-aliging ball bearings