10 Wheel Ball Bearings for many applications, this is a popular size that could be used in many RC Cars and Trucks or any application that uses this size 8mm x 14mm x 4mm. 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.