6200-2RS Sealed Ball Bearing Premium ABEC-5 Quality with Si3N4 Ceramic Balls (Silicon Nitride) 10mm x 30mm x 9mm 6200-2RS Sealed Ball Bearing is radial, deep groove ball bearing,6200-2RS bearing is made of Stainless Steel with Ceramic Balls (Si3N4) and Nylon Cage,bearing is closed with rubber seals to protect the bearing from dust or any possible contamination,6200-2RS bearing is sealed and self lubricated,the quality is set to EMQ (Premium ABEC-5 quality) to ensure high speed,6200-2RS bearings is lubricated with grease.