Brisk AR12ZS Premium Racing spark plug for race car engines. Features a 10mm thread, 19mm (3/4in) reach, and 16mm (5/8in) hex with a gasket seat. Heat Range 12, resistor, with a surface discharge design for improved spark and combustion in high-performance racing engines. Ideal for high-compression or forced induction setups. Recommended torque: 7-10 ft-lbs. Gap: 0.020-0.035 inches. Sold as each.