ABEC-5 Ball Bearings 3/16"x3/8"x1/8" Stainless Steel and Ceramic Balls 10 Bearings 10 Stainless Steel Bearings with Ceramic Balls ABEC-5 quality, this is a popular size that could be used in many application that uses this size 3/16"x 3/8"x 1/8", each bearing has 2 metal shields to protect the bearing from dust or any possible contamination, also bearings are pre-lubricated with grease.