Laser Iridium Ngk. single iridium plugs were designed specifically for the performance enthusiast. Fine wire center electrode guarantees high long service life and a consistently stable spark. Iridium alloy has an extremely high melting point, well-matched to today's high-tech, high performance engines. Trivalent metal plating provides stronger anti-corrosion and anti-seizing properties Corrugated ribs prevent flashover Pure alumina silicate ceramic insulator, provides stronger strength and better heat transfer Copper core aids in heat removal Triple seals prevent leakage *By request/order.