61904-2RS Ceramic Hybrid C3 Ball Bearing Chrome Steel and Ceramic Balls 20mm x 37mm x 9mm 61904-2RS Hybrid ceramic chrome steel sealed bearing with ZrO2 Ceramic Balls Electric motor quality, 61904-2RS is a popular size that could be used in many applications that uses this size 20mm x 37mm x 9mm, 61904-2RS is closed with 2 Rubber Seals, bearing is double sealed and one seal from each side to protect the bearing from dust or any possible contamination, also bearing is pre-lubricated with grease, Bearing has industrial packaging.