5 x 11 for Tamiya Traxxas One Ball Bearing 5 x 11 x 4 Tamiya Traxxas Ball Bearings, this is a popular size that could be used in many Vintage Radio Control Cars and trucks, Bearing 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.