For over 25 years Innovators West has produced high quality SFI 18.1 certified harmonic balancers right here in the United States with all American components. With a standard all aluminum case design for lower reciprocating weight, stress-proof steel hub and 1040 steel internal inertia rings for outstanding durability, Innovators West Balancers are a great investment for your street or race vehicle. Inside the light weight billet aluminum cover is a free floating wet friction clutch pack assembly that utilizes spring loaded inertia rings to dampen crankshaft harmonics over a wide RPM range. The rings work in conjunction with clutches to provide outstanding dampening action. That action does generate some heat, and we use a small amount of fluid inside that acts as a lubricant as well as dissipates heat to the outer body.