Brisk DOR15LGS Premium Racing spark plug for race car engines. Features a 14mm thread, 19mm (3/4in) reach, and 16mm (5/8in) hex with a gasket seat. Heat Range 15, resistor, with a surface discharge design for enhanced spark and combustion efficiency in high-performance racing engines. Suited for high-performance turbo or nitrous setups. Recommended torque: 15-22 ft-lbs. Gap: 0.020-0.035 inches. Sold as each.