Built out of steel in the good old USA and black zinc chromate finished with laser etched timing marks, these dampers EXCEED SFI 18.1 specs. Designed with absolute precision in mind, the ATI Super Dampers are without a doubt the highest quality harmonic balancers built for diesel engines of all builds. But if you have made significant changes to your engine and are looking to optimize and balance out everything you've put into it (which includes blood, sweat, and broken knuckles) then you NEED a harmonic balancer, and we've found that the ATI units are unsurpassed. By eliminating torsional vibration at the crankcase, your truck will come alive faster and run smoother.