NGK 3108 DPR6EB-9 Standard Spark Plug. NGK&';s Standard Plugs are Constructed for Longer Life and Optimum Performance. Fits Yamaha outboard engines. Specifications: Shell Thread Size: 12mm Thread Pitch: 1.25mm Seat Type: Gasket Resistor: Yes Resistor Value: 5K Ohm Reach: 19mm (3/4") Hex Size: 18mm Terminal Type: Solid Overall Height: ISO Gap: .035" (0.9mm) Center Electrode Material: Nickel Type: Standard Size: 2.5mm Projection: Projected Ground Electrode Material: Nickel Type: Standard Quantity: 1 Torque Specs: Cast Iron: 18-25.3 lb. ft. Aluminum: 18-21.6 lb. ft. Brand: NGK Heat Range: 6 Longevity: 30k Miles