Spark plug designed to operate over a much wider heat range than ordinary plugs with resists carbon buildup and pre-ignition. High alumina ceramics for better heat transfer and electrical insulation, solid copper core and nickel tipped electrode provide a longer plus life. Patented triple gasket sealing process eliminates the possibility of combustion gas leakage. Solid copper core for greater spark, corrugated ribs on insulator prevents flashover, zinc dipped shell prevents corrosion. For Yamaha engines. Specifications: Thread size – 14 mm, Thread pitch – 1,25 mm, Resistor value – 5000 Ohms, Reach – 26,5 mm, Heat range – 5, Longevity – 30.000 miles.