The Assault RC Revolver Series 7x19x6mm Chrome Steel Engine Bearing provides the maximum performance and reliability to your racing engine at a competitive price. The bearing contains 7 Abec5 52100 Chrome Steel Balls riding on an advanced poly inner cage and Chrome Steel 52100 Rings. It has dual rubber seals but to allow for proper lubrication from the oil in your fuel we suggest removing the shield that faces in towards the engine for proper lubrication.