AEM 30-2853 High Output Smart Coil This deliver a powerful, long duration spark and are ideal for use in high-boost or high compression engines Massive spark energy, up to 118 mJ; Up to 41 Kilovolts output voltage, without a CDI Adjustable backlighting via a dial on the back of the gauge; weather and shock proof design Can be mounted directly to the engine Before installing the AEM High Output Coil, disconnect the battery cables; improper handling may cause severe electric shock which may result in injury or death