... .ISO 9001 2.High quality,low price Single Row SL bearingLinear contact exists between the roller ... stopping ringsSL0450...PXCylindrical roller bearings with stopping rings ,single face sealedSL0450...PPXCylindrical roller bearings with stopping rings, ... stopping ringsSL04...PXCylindrical roller bearings with stopping rings, single face sealedSL04...PPXCylindrical roller bearings with stopping rings , ...