Daytona Twin Tec High Output Single Fire Coil For Harley This high output single fire coil is compatible with most aftermarket single fire ignition systems. Features: 3-ohm primary coil is compatible with all Twin Tec and most aftermarket single-fire ignitions Easy installation, fits stock bracket and cover for most applications Compatible with fuel injected and carbureted applications Ignition coils exceed OE specifications 2.5 on center mounting holes Note: Single fire ignition required for installation, sold separately.