Ultra fine wire iridium firing pin and iridium tapered ground electrode inlay provide higher performance. Laser weld provides superior retention of iridium alloy to the ground electrode. 0.6 mm fine wire firing pin for better ignitability and durability. Copper core helps prevent pre-ignition and fouling. Nickel-plated shell and rolled threads provide anti-seize and corrosion protection. Ribbed insulator prevents flashover.