S686-2RS Sealed Ball Bearing ABEC-5 Quality with Si3N4 Ceramic Balls 6mm x 13mm x 6mm S686-2RS Bearing is double sealed, radial, deep groove ball bearing,bearing is made of Stainless Steel with Ceramic Balls (Si3N4),bearings is sealed and self lubricated, the quality is set to EMQ (ABEC-5 quality),inner diameter is 6mm, outer diameter is 13mm and width is 6mm.