Firearms enthusiasts can now pack some heat with the hottest spark plug wires on the market to date, the Taylor/Sumax made 9mm Firepower spark plug wires. These black high tension wires feature silver 9mm Gun-style spark plug boots. All wires fire intermittently no matter what coil or ignition you may have. That is why you see carbon on your plugs. These 9mm Firepower wires provide a solid stream of fire power eliminating the carbon on your plugs. This results in more horsepower, more torque and better mileage. Your bike will start and run better than ever before! They are compatible with all Harley ignition systems. You have a choice of stock replacement kits or universal sets where you terminate the wires to your desired length.