The plugs used by winning racers.
These NGK Iridium IX spark plugs feature an ultra fine center electrode that's designed not too thin to ensure maximum durability and life of the spark plug and not too thick for an accurate and consistent spark. They represent the ultimate evolution of spark plug technology and performance. Iridium is significantly stronger than any metal used in spark plugs today. It's the hardest metal used (in fact, iridium is 6 times harder than platinum) which has allowed NGK engineers to design an ultra fine center electrode reducing the voltage requirement for spark.
Spark Plug, Iridium IX, Gasket Seat, 10mm Thread, .750 in. Reach, Resistor, Each