R6ZZ Shielded Ball Bearings, R6ZZ inner diameter is 3/8", R6ZZ outer diameter is 7/8" and the R6ZZ width is 9/32", R6ZZ is a popular size that could be used in many applications, Bearings are made of Chrome Steel, each R6ZZ bearing has 2 metal shields to protect the bearing from dust or any possible contamination, R6ZZ bearings are pre-lubricated with grease, Bearings are packed in one plastic tube.