8 x 22 x 11 Skateboard Sealed Ball Bearing 8 x 22 x 11 Skateboard Sealed Ball Bearing, bearing is Carbon Steel, 8 x 22 x 11 bearing has built-in rubber seals in order to protect the moving elements from dust or any possible contamination, this is self lubricated bearings (bearing is already lubricated with oil), oil lubrication is to ensure fastest possible speeds.