NGK 93759 DILFR5A11 Laser Iridium Spark Plug, Pack of 4 Laser welded Iridium center electrode tip ensures high durability and greater spark Platinum disc welded to backside of ground electrode provides long life Longer insulator nose prevents fouling, Corrugated ribs on insulator prevents flashover, and the triple gasket seal eliminates combustion gas leakage Longer insulator nose prevents fouling, Corrugated ribs on insulator prevents flashover, and the triple gasket seal eliminates combustion gas leakage Faster starts and quicker acceleration