R8-2RS Sealed Ball Bearing 1/2" x 1 1/8" x 5/16" inch One Bearing R8-2RS Sealed Ball Bearing, R8-2RS Bearing is made of Chrome Steel, this R8-2RS bearing is sealed with rubber seals to protect the bearing from dust or any possible contamination, R8-2RS bearing is self lubricated bearings (bearings are already greased).