Holley's Distributor less Ignition System (DIS) offers many advantages over a conventional distributor and ignition box including: Improved starting and idle quality, more spark energy-especially important when using power adders to maximize horsepower, cleaner emissions, system longevity-more moving parts, tuning simplicity and accuracy. Maximize your HP or Dominator EFI system, take control of your ignition, and eliminate the need for an expensive, separate ignition box! It allows for all timing functions to be programmed within the Holley EFI system, rather than having a separate box control retards and other timing functions. The system comes configured as a waste fire system utilizing the following components: Trigger wheel and sensor kit-precision engineered and manufactured with tight tolerances, this wheel is designed to be installed on the crank pulley or harmonic balancer and offers unmatched timing stability and accuracy. The Holley dual tower coils provide higher spark energy than even high power single racing coils, while still providing the durability of a factory ignition system. Excellent for any supercharged, turbo charged, nitrous or high compression engines, or anyone wanting the unmatched timing accuracy and spark energy this system offers.