R2-5 2RS Sealed Ball Bearings 1/8" x 5/16" x 9/64" inch Lot of 10 Bearings R2-5 2RS Sealed Ball Bearings, this is a popular size that could be used in many application that uses this size 1/8" x 5/16" x 9/64". Bearings are made of Chrome Steel, each bearing is rubber sealed from both sides to protect the bearing from dust or any possible contamination, also bearings are pre-lubricated with grease.