NGK BPR6HS-10 spark plug for various makes and models.NGK traditional plugs are constructed for longer life and optimum performance. Corrugated ribs prevent flashover. NGK uses only the purest alumina silicate in its ceramic insulator which give all NGK plugs greater strength and better heat transfer. Copper cored and triple sealed to further aid in heat removal and prevent interior leakage. NGK2633 Thread Size 14mm Reach 12.7mm (1/2 inch) Hex Size 20.6mm (13/16 inch) Gap 1.02mm (.040 inch) Heat Range 6