ABEC-5 Ball Bearings 8x12x3.5 Stainless Steel Lot of 10 Bearings High Quality 10 bearings Stainless Steel Ball Bearings ABEC-5 quality, this is a popular size that could be used in many application that uses this size 8mm x 12mm x 3.5mm. Bearings are made of Stainless Steel and can rotate up to 46,000 rpm, each bearing has 2 metal shields to protect the bearing from dust or any possible contamination, also bearings are pre-lubricated with grease.