... / closure: open ball bearing, Z, ZZ, RS, 2RS,2RZBall bearings snap ring: N, NRTolerance codes: ABEC-1, ABEC-3, ABEC-5, ABEC ... RS, 2RS.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 NR.In different radial clearances ...