NGK iridium plugs represent the ultimate evolution of spark plug technology and performance. The iridium center electrode is both stronger and harder than platinum. This tapered cut iridium center electrode reduces the voltage requirement for spark. This allows for a brighter, stronger spark from your existing ignition system. A platinum tipped ground electrode further contributes toward the extreme longevity of this plug. Technical Specifications - Extreme Long Life Laser Iridium Plug, 14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Solid Terminal, Projected Tip, Iridium Tipped Fine Wire Center Electrode with Platinum Tipped Ground Electrode, .044" (1.1mm) Gap