NGK 4322 BR8HS Nickel Spark Plug Traditional Spark Plug, 14mm Thread Size, 12.7mm (1/2") Reach, 13/16" (20.6mm) Hex Size, Gasket Seat, Resistor, Removable Terminal Nut, .028" (0.7mm) Gap, Heat Range 6 NGK traditional plugs are constructed for longer life and optimum performance. Corrugated ribs prevent flashover. NGK uses only the purest alumina silicate in its ceramic insulator which give all NGK plugs greater strength and better heat transfer. Copper cored and triple sealed to further aid in heat removal and prevent interior leakage