S606-2RS Bearing is double sealed, radial, deep groove ball bearing,bearing is made of Stainless Steel with Ceramic Balls (Si3N4) and nylon cage,S606-2RS bearing is closed with rubber seals to protect the bearing from dust or any possible contamination,bearings is sealed and self lubricated, the quality is set to EMQ (Premium ABEC-5 quality),S606-2RS bearing is lubricated with grease.