NGK 6684 Spark Plug , black;

Designed specifically for the performance enthusiast, Iridium IX offers extreme ignitability, improved throttle response and superior anti-fouling. The 0.6mm laser welded fine iridium tip ensures high durability and a consistently stable spark and the tapered ground electrode minimizes electrical quenching effect. Longer insulator nose prevents fouling, the corrugated ribs on insulator prevents flashover, and a triple gasket seal eliminates combustion gas leakage. Iridium alloy has extremely high melting point, giving it high durability to heat and electrical wear, perfect for today's high-performance engines. Trivalent metal plating has superior anti-corrosion and anti-seizing properties.