S6204 Open Ball Bearing Premium ABEC-5 Quality with Si3N4 Ceramic Balls (Silicon Nitride) 20mm x 47mm x 14mm S6204 open stainless steel ball bearing, radial and deep groove ball bearing, S6204 bearing is made of Stainless Steel with Ceramic Balls (Si3N4) and Stainless Steel Cage, the quality is set to EMQ (Premium ABEC-5 quality) to ensure high speed, inner diameter is 20mm, outer diameter is 47mm and width is 14mm.