The PRO/RACE "ALL STEEL" Harmonic Dampers are designed and manufactured for racing and high performance street applications and are available for a wide range of engines. The PRO/RACE Damper is a direct replacement for the cast iron stock damper which is no longer permitted by most racing sanctioning bodies due to the danger of fracture and high speed disintegration or separation of the inertia ring from the hub. This problem is eliminated with a PRO/RACE Damper. The PRO/RACE "ALL STEEL" Harmonic Damper is also a must for all belt driven supercharger applications due to the additional torque loads on the damper hub and keyway which results in failure in nearly 100% of all blower installations with a stock damper.