S6904-2RS Stainless Steel Sealed Ball Bearing 20mm x 37mm x 9mm S6904-2RS radial and deep groove ball bearing,bearing is closed with rubber seals to protect the bearing from dust or any possible contamination, S6904-2RS bearings is sealed and self lubricated, S6904-2RS bearing is made of Stainless Steel, bearings is lubricated with grease.