Daytona Twin Tec Ignition Power Relay Kit for High Compression Engines fits Harley - Daytona Twin Tec 684962This relay kit from Daytona Twin Tec improves or eliminates the voltage drop on big inch or high compression engines with single fire ignitions Single fire ignitions may exhibit difficulty starting when starter motor draws more current than the electrical system was originally designed for Suitable for Daytona Twin Tec models 1005, 1005S, 1006 and 1007