4 x 10 x 3 Ball Bearing Lot of 10 Bearings 4 x 10 x 3 Wheel Ball Bearings for many applications, this is a popular size that could be used in many RC Cars and Trucks, Bearings are made of Chrome Steel, each bearing has 2 metal shields 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.