NGK DILFR6D11 Double Fine Electrode Iridium Spark Plug provide superior ignitability and long service life. Fine wire iridium tipped center electrode and fine wire platinum tipped ground electrode ensures slow wear rate providing stable idle, superior anti fouling, improved fuel efficiency and lower emissions. Trivalent metal plating provides superior anti-corrosion and anti-seizing properties. Corrugated ribs prevent flashover. Pure alumina silicate ceramic insulator, provides superior strength and better heat transfer. Copper core aids in heat removal. Triple seals prevent leakage. Specifications: Shell - Thread Diameter: 14mm Thread Pitch: 1.25mm Seat Type: Gasket Reach: 26.5mm (1.04") Hex Size: 5/8" (16mm) Terminal Type: Solid Overall Height: ISO Gap:.043" (1.1mm) Center Electrode - Material: Iridium Type: Fine Wire Size: 0.6mm Projection: Projected Ground Electrode - Material: Platinum Type: Fine Wire Shape: Taper Cut Resistor: Yes Resistor Value: 5k Ohm Heat Range: 6 Torque Specs Cast Iron: 18-25.3 lb. ft. Aluminum: 18-21.6 lb. ft. Longevity: 100k Miles Part Number: DILFR6D11.