S6205 Open Ball Bearing ABEC-3 Quality with Si3N4 Ceramic Balls (Silicon Nitride) 25mm x 52mm x 15mm S6205 open stainless steel ball bearing, radial and deep groove ball bearing,S6205 bearing is made of Stainless Steel with Ceramic Balls (Si3N4) and Nylon Cage,the quality is set to EMQ (ABEC-3 quality) to ensure high speed,inner diameter is 25mm, outer diameter is 52mm and width is 15mm.