NGK DPR5EA-9 (2887) Standard Plugs are Constructed for Longer Life and Optimum Performance.. 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 Thread Size: 12mm Thread Pitch: 1.25mm Seat type: Gasket Resistor Value: 5K Ohm Reach: 19mm (3/4") Hex Size:18mm Terminal Type: Threaded Stud Overall Height: ISO Gap: (0.9mm)