R155ZZ Ball Bearings 5/32" x 5/16" x 1/8" 10 Bearings 10 R155ZZ Shielded Bearings, R155ZZ inner diameter is 5/32", R155ZZ outer diameter is 5/16" and the R155ZZ width is 1/8", R155ZZ is a popular size that could be used in many applications, each R155ZZ bearing has 2 metal shields to protect the bearing from dust or any possible contamination, also R155ZZ bearings are pre-lubricated with grease.