6903RS Ball Sealed Ball Bearing 17mm x30mm x 7mm 6903RS Ball Sealed Ball Bearing, inner diameter is 17mm, outer diameter is 30mm and width is 7mm,6903RS is a popular size that could be used in many applications, Bearing is made of Chrome Steel,6903RS bearing has 2 built-in rubber seals to protect the bearing from dust or any possible contamination, bearing is pre-lubricated with grease.