Daytona Twin Tec Model 1007 External Ignition For Harley This kit is highly recommended for demanding race applications where extreme engine temps would reduce the reliability of an internal module. Designed to correct starting problems in motorcycles with high compression ratios or large displacement engines that use Twin Tec single-fire ignitions Fully Programmable Ignition. The combined draw of the starter motor, single fire coil and long length of the wire between the battery, engine stop-run switch and the coil may leave too little energy at the coil to provide enough spark to fire the engine. Power Relay kit solves the problem by supplying full battery voltage to the coil. Kit includes high-quality relay, wire, and all required terminals. Features: Wide timing advance adjustment range accommodates stock to highly modified engines Digitally set RPM limit (100 RPM steps) Selectable single or dual fire mode Selectable multi-spark mode for quick starting and smooth cruise Coil outputs protected against short circuits Optional USB interface and software for programming custom advance curve Billet aluminum housing with black anodized finish Easy plug-in installation