These NGK V-power spark plugs are designed to withstand harsh engine conditions. They feature a unique v-cut in the center electrode. This design directs the spark to the edge of the electrode which aids in faster spark development, increased ignitability and reducing quenching.  Special insulator nose configurations improves throttle response. Corrugated ribs prevents flashover. Pure alumina silicate ceramic insulator provides better heat transfer and provides superior strength. Trivalent metal plating provides anti-corrosion and anti-seizing properties. Copper core aids in heat removal. Triple seals prevents leakage. V-Groove increases ignitability. Set of 8.