Denso # 47020.4mm Iridium Center Electrode0.7mm Platinum Ground ElectrodeLarger spark translates to more power and superior fuel economy0.4 mm iridium center electrode, world's smallest diameter that maximizes firing potential0.7 mm needle tip ground electrode, promotes higher spark energy and less heat quenchingDENSO patented 360 degree laser welding process, ensuring exceptional quality bond and structural strength with the iridium center electrode.Durability of an OE style plug combined with Power & Torque of high performance. Unparalleled, the Iridium TT is designed to last beyond 100,000 miles - providing coverage for most makes and models on the road today.