FAST E6 Digital CD ignition boxes are engineered to provide a solution for a digital electronic CD Ignition that would work with FAST EFI components. The boxes feature multiple-spark functionality, meaning the engine will fire multiple sparks per cylinder while the engine is below 3,000 rpm. This feature provides a more complete burning of the fuel in the combustion chamber, resulting in a smoother running engine and better fuel economy. These ignition boxes are electronic fuel injection friendly--and specifically designed to work with FAST XFI, XFI Sportsman, EZ-EFI and EZ-EFI 2.0 systems. The engineers at FAST also designed the FAST E6 Digital CD ignition boxes to be fully compatible with all carbureted applications.