Coil Smart Big Wire Kit Black Universal Use With Holley Or EFI Systems MSD IgnitionIt is compatible with Holley EFI and many other aftermarket electronic fuel injection systems and will run on traditional 12 or 16 volt electrical systems found in race applications. The MSD Smart Coil Big Wire Kit allows you to run dwell time over 5 milliseconds to gain the most of the Smart Coils. It will allow the coil to produce 50,000 peak voltage and peak energy of 190 millijoules, this means you get hotter spark at the plug to burn the maximum