1628-2RS Sealed Ball Bearing 5/8" x 1 5/8" x 1/2" inch 1628-2RS is double sealed, radial, deep groove ball bearing,1628-2RS bearing is made of Chrome Steel with chrome steel balls and steel cage, bearing is closed with rubber seals to protect the bearing from dust or any possible contamination,1628-2RS bearing is sealed and self lubricated,the 1628-2RS inner diameter is 5/8", the 1628-2RS outer diameter is 1 5/8" and the 1628-2RS width is 1/2", the quality is set to EMQ (electric motor quality) to ensure high speed,1628-2RS bearing is lubricated with grease.