SR156ZZ Stainless Steel Ball Bearing 3/16" x 5/16" x 1/8" inch SR156ZZ Stainless Steel Ball Bearing, this is a popular size that could be used in many applications that uses this size 3/16" x 5/16" x 1/8", Bearing is made of Stainless Steel, each bearing has 2 metal shields to protect the bearing from dust or any possible contamination, also bearing is pre-lubricated with grease.