6918-2RS Sealed Ball Bearing 90mm x 125mm x 18mm One Bearing 6918-2RS Bearing is double sealed, radial and deep groove ball bearing, bearing is made of Chrome Steel with chrome steel balls and steel cage,6918-2RS bearing is closed with rubber seals to protect the bearing from dust or any possible contamination,6918-2RS bearing is sealed and self lubricated, the quality is set to EMQ (electric motor quality) to ensure high speed, 6918-2RS bearing is lubricated with greased.