Designed with a heavy duty insulator that provides unparalleled dielectric strength and thermal conductivity under extreme temperatures; Five-rib design prevents flashover while decreasing voltage loss; Copper glass seal bonds the center electrode and insulator together for a gas-tight seal; Platinum center electrode utilizes platinum to shrink the surface area of the center electrode tip for maximum firing performance and minimum voltage requirements; Platinum ground electrode resists gas and electrical erosion and corrosion extending service intervals to 60,000 miles