6203-2RS C3 Ceramic Hybrid Sealed Ball Bearing Chrome Steel and Ceramic Balls 17mm x 40mm x 12mm 6203-2RS C3 Ceramic Hybrid Ball Bearing with ZrO2 Ceramic Balls Electric motor quality, each 6203-2RS bearing is closed with 2 Rubber Seals, 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 6203-2RS has industrial packaging.