DK Custom Products 409 PRO RACE Plug Wires Universal Fit BLACK "409" PRO RACE wires provide continuous heat protection up to 600 degrees Farenheit. The 10.4mm wires deliver 102,000 volts dielectric strength. Low Profile 100% silicone PRO BOOTS feature vibration proof double spring locking spark plug terminals. Spiral-Wound core with 350 ohms per foot resistance for EMI and RFI suppression delivers theMaximum Fire Powerwithout radio interference and recommended for use with electronic ignition systems found on Harley-Davidsons. ***These will NOT fit 1995-2003 Sportster Coils***