Clutch Masters Aluminum Flywheels are made of 6061 T6 aluminum making it extremely strong and light at the same time. Their flywheels are SFI certified and tested to ensure safety and quality. Lightweight flywheels will help the engine spin more freely because of the smaller mass that the engine needs to rotate while going through the engine's rpm range. This can also reduce lag in turbo motors and increase supercharger efficiency on supercharged vehicles. Naturally aspirated motors can also benefit greatly through an increase in torque in the mid range. Each flywheel is CNC machined and balanced for precise fitment and operation on any vehicle.