37-R0409B-8 Iridium Racing Plug, 10mm Thread Size, Half Thread Type - 12.7mm (1/2") Threaded, 19mm (3/4") Total Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Stud Terminal Threads, Ultra Fine Wire Iridium Tipped Center Electrode, Fine Wire Nickel Angled Angled Ground Electrode, .028" (0.7mm) Gap, Heat Range 8. NOTE: Does not Include Terminal Nut, if necessary, order part #067606-0051
Fine wire racing plugs are designed to give you a stronger spark from your existing ignition system. Slightly recessed fine wire iridium center electrode requires less voltage to ionize(jump) the plug gap. This allows a stronger spark which will better ignite the air fuel mixture leading to more power. The iridium center electrode offers increased durability. Fine wire nickel ground electrode to reduce quenching. Hand made in Japan and constructed to withstand the most extreme racing environments.