... ,flange ball bearings,self-aligning ball bearings.with less coefficient of friction, high limiting speed ... bearing, Z, ZZ, RS, 2RS,2RZBall bearings snap ring: N, NRTolerance codes: ABEC-1, ABEC-3, ... With one or two side metal shields Z and ZZ (2Z).With a snap ring groove in outer ring N.With a snap ring ... groove in outer ring and external snap ring ...