NGK nickel spark plugs feature a specially designed v-groove center electrode, improving ignitability and reducing quenching. The 98% pure copper core delivers increased heat dissipation for more reliable starts and reduced risk of overheating. Features: High-grade alumina silicate ceramic Creates a stronger insulator to reduce dielectric punchthrough (caused by spark exiting through side of ceramic) Cold rolled threads Prevents cross-threading and damage to cylinder heads 98% pure copper core Increased heat dissipation for reliable starts, prevents spark plug overheating Trivalent metal plating No antiseize required Ground electrode Designed to reduced quenching effect resulting in better ignition performance DS 70 2009-2018, DS 90 2002-2018