Fidanza Aluminum Flywheels are made from 6061 T6 billet aluminum for superior strength and weight reduction. Fidanza flywheels are CNC machined at a constant speed for precise fit and finish, and feature a replaceable 1045 high-carbon steel friction plate with AN military-grade fasteners and a hardened 1050 ring gear. You will never have to replace your flywheel again as you can just swap friction plates, and reinstall. All these features make this a quality lightweight flywheel at a great price. The Fidanza Mini Cooper & Cooper S flywheel is SFI Certified, and weighs 11 pounds, resulting in no check engine lights or misfire codes.