Champion RER8WYCB4 (9408) Iridium Spark Plug, Pack of 1 Extremely fine-wire Iridium center electrode laser-locked to center electrode Platinum ground to ensure high performance and long life Exclusive Heat-Active Alloy allows electrodes to reach optimal temperature quickly Greatest engine performance regardless of engine type or ignition system Maintains stable operating temperature under all engine loads Focused spark for maximum power Exclusive Heat-Active alloy maintains stable operating temperature under all load conditions Faster throttle response