61904-2RS Sealed Ball Bearing 20mm x 37mm x 9mm One Bearing 61904-2RS Sealed Ball Bearing, inner diameter is 20mm, outer diameter is 37mm and width is 9mm,bearing is a popular size that could be used in many applications,Bearing is made of Chrome Steel,6904-2RS bearing has 2 built-in rubber seals to protect the bearing from dust or any possible contamination,6904-2RS bearing is pre-lubricated with grease,the 6904-2RS ball bearing is packed in one HD plastic bag.