6708ZZ Shielded Ball Bearing 40mm x 50mm x 6mm 6708ZZ Shielded Ball Bearing, Bearing inner diameter is 40mm, Bearing outer diameter is 50mm and Bearing width is 6mm, 6708ZZ bearings is a popular size that could be used in many RC Cars and Trucks, Bearings is made of Chrome Steel, each bearing has 2 metal shields to protect the bearing from dust or any possible contamination, also bearing is pre-lubricated with grease.