NGK ITR4A15 Spark Plug NGK Laser Iridium spark plugs offer the best combination of performance and longevity. The iridium tipped center electrode provides durability six times harder than platinum. NGKs high-grade pure alumina ceramic and 98 pure copper core prevents the spark plug from overheating while providing reliable starts. Laser iridium plugs are tested to the highest standards to ensure quality and durability. Actual OE or equivalent replacement spark plug. Part Number ITR4A15 Stock Num