627-2RS Sealed Ball Bearing ABEC-5 Quality with Ceramic Balls 7mm x 22mm x 7mm 16 Bearings 627-2RS Sealed Ball Bearing is double sealed, radial and deep groove ball bearing,627-2RS bearings are made of Chrome Steel with Ceramic Balls and Chrome steel cage,627-2RS bearing are closed with rubber seals to protect the bearing from dust or any possible contamination,627-2RS bearings are sealed and self lubricated,the quality is set to EMQ (ABEC-5 quality) to ensure high speeds,627-2RS bearings are lubricated with Oil.