NGK Laser Iridium Spark Plugs are the Premium OE Spark Plug Design. They Feature a Laser Welded 0.8mm Iridium Center Electrode along with Laser Welded Platinum on the Ground Electrode Providing the Strongest Ignitability and the Longest Life Possible. Trivalent Shell Plating Provides Superior Anti-Corrosive & Anti-Seizing Properties.