Ball Bearings 8x12x3.5 Sealed Lot of 10 Bearings 10 Sealed Ball Bearings, this is a popular size that could be used in many RC wheel and motor applications that uses this size 8mm x 12mm x 3.5mm. Bearings are can rotate up to 46,000 rpm, each bearing has 2 Seals to protect the bearing from dust or any possible contamination, also bearings are pre-lubricated with grease, Bearings are packed 10 bearings in one plastic tube.