6000-2RS Sealed Ball Bearing ABEC-5 Quality with Si3N4 Ceramic Balls Nylon Cage 6000-2RS Bearing is double sealed, radial and deep groove ball bearing,6000-2RS bearing is made of Chrome Steel with Ceramic Balls (Si3N4) and Nylon cage,bearing is closed with rubber seals to protect the bearing from dust or any possible contamination,6000-2RS bearing is sealed and self lubricated,the quality is set to EMQ (ABEC-5 quality) to ensure high speeds, 6000-2RS bearings is lubricated with grease.