6203-2RS Sealed Ball Bearing 17 x 40 x 12 mm 6203-2RS Sealed Ball Bearing, the inner diameter is 17mm, outer diameter is 40mm and the width is 12mm, Bearing is made of Chrome Steel, each bearing has 2 Rubber Seals to protect the bearing from dust or any possible contamination, also bearing is pre-lubricated with grease.