Sumax Thundervolt Black Spark Plug Wires 69031 More horsepower, more miles per gallon All plug wires fire intermittently causing plugs to carbon up except for Thundervolts As your bikes idles, the plugs are being cleaned Ferrite spiral wound core with a blend of copper/nickel alloy is bonded by a conductive acrylic cover Pro boots feature vibration proof double spring locking spark plug terminals