Superior construction, longer life, and optimum performance - all are standard with NGK, the brand specified as the #1 spark plug for performance. Corrugated ribs help prevent "flashover" of spark which can lead to harmful misfires and rob you of performance Highly pure alumina silicate insulator ensures dielectric strength and incredible physical strength - sophisticated ceramic properties ensure proper heat transfer Triple gasket sealing process virtually eliminates the possibility of combustion gas leakage back through the shell - other manufacturers use only one or two seals Solid copper core ensures greater spark and heat transfer Longer insulator nose, also called a "power tip", helps prevent loading up or fouling even after prolonged periods of idling or at slow speeds Shells are double dipped in a tough, corrosion-resistant zinc chromate coating ensuring maximum rust resistance