Ball Bearings 6308RS 40mm x 90mm x 23mm 6308RS Ball Bearing, the 6308RS inner diameter is 40 mm, 6308RS outer diameter is 90 mm and the 6308RS width is 23mm, 6308RS is a popular size that could be used in many applications,6308RS Bearings are made of Chrome Steel, 6308RS can rotate up to 5300 rpm, 6308RS bearing has 2 Blue Rubber Seals to protect the bearing from dust or any possible contamination, 6308RS bearings are pre-lubricated with grease.