Ball Bearings 2.5x8x2.8 Lot of 10 Bearings High Quality 10 Ball Bearings, this is a popular size that could be used in many application that uses this size 2.5mm x 8mm x 2.8mm. Bearings are made of Chrome Steel and can rotate up to 80,000 rpm, Bearings are packed 10 bearings in one plastic tube.