Make sure of an immediate start and smooth running from your engine with the authentic NGK BR7HS-10 spark plug. Made to NGK's high standards, it gives a steady spark, outstanding resistance to thermal stress and correct combustion across the whole rev range. Technical Specification Manufacturer: NGK Product Code / Stock No.: BR7HS-10 / 1098 Thread Diameter: 14 mm Thread Length (Reach): 12.7 mm (Short reach) Hex Size: 20.8 mm (13/16") Electrode Gap: 1.0 mm Heat Range: 7 Electrode Type: Nickel with a copper core