NGK Spark Plugs - Standard NGK standard plugs are constructed for longer life and optimum performance. Features Nickel alloy tip for longer life Trivalent metal plating provides superior anti-corrosion and anti-seizing properties Corrugated ribs prevent flashover Pure alumina silicate ceramic insulator provides superior strength and better heat transfer Copper core aids in heat removal Triple seals prevent leakage 30,000 mile service life