Denso Spark Plug Denso's standard plugs have always offered a patented U-groove ground electrode producing for a larger, hotter spark. Copper core for better thermal conductivity. Machine rolled threads to reduce cross-threading and seizing . The plug insulator is constructed of purified alumina powder for extreme stress with 5 ribs to prevent flashover. Product Features:U-Groove Ground Electrode Promotes Ignitability and Decreases QuenchingFully Projected Insulator Reduces Carbon FoulingMachine Rolled Threads Prevent Seizing or Cross Threading During Installation and Removal100% Pre-Fired to Assure the Highest Quality PossiblePurified Alumina Powder Insulator Provides Exceptional Strength and Thermal ConductivityFive Rib Insulator Prevents FlashoverCopper-Glass Seal Bonds Center Electrode and Insulator for a Gas-Tight Seal
