THIS ITEM SHIPS FREE! Patented ATI Super Damper standard harmonic balancers are the only crankshaft dampers designed exclusively for high performance engines. Inner and outer shells are available in aluminum or steel, and contain a steel inertia weight. The inertia weights have six (2-ring design) or eight (3-ring design) computer-machined grooves to retain the proper durometer O-rings (dyno tested for each application). Whether you race or just drive on the street, ATI harmonic balancers are the perfect choice.Features include:* Eliminates torsional crankshaft vibrations* Exceeds SFI 18.1 specs* Black zinc chromate finished* OEM equipment on a variety of crate engines* Tunable, rebuildable, and extremely efficient at all rpm* Laser-engraved 360 degree timing marks* Supercharger and power steering drive pulleys available for some applications *Please note that this pulley is a smaller diameter than the OEM K24 units. Serpentine belt sizes will need to be changed depending on your set up.