SFR155-2RS Ball Bearing Stainless Steel With Flanged 5/32" x 5/16" x 1/8" Inch SFR155-2RS Stainless Steel With Flanged Ball Bearing, this is a popular size that could be used in many application that uses this size 5/32" x 5/16" x 1/8". each bearing is rubber sealed from both sides to protect the bearing from dust or any possible contamination, also bearing is pre-lubricated with grease.