6201-2RS is double sealed, radial, deep groove ball bearings,6201-2RS bearing is made of Stainless Steel with Ceramic Balls (Si3N4) and Nylon Cage,6201-2RS bearing is closed with rubber seals to protect the bearing from dust or any possible contamination,6201-2RS bearing is sealed and self lubricated,the quality is set to EMQ (Premium ABEC-5 quality) to ensure high speed,6201-2RS bearings is lubricated with grease.