6801RS Sealed Ball Bearing 12 x 21 x 5 mm One Bearing Sealed Ball Bearing is double sealed, radial and deep groove ball bearing,6801RS 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,6801RS bearing is sealed and self lubricated,the quality is set to EMQ (electric motor quality) to ensure high speed,6801RS bearing is lubricated with greased.