The ground electrode is cut-back from the center electrode to provide a gap. The face of the ground electrode is concave to provide a constant gap to the center electrode. This plug is designed use in all aftermarket cylinder heads used in different types of racing venues including oval and road racing. Product Features:Opens spark face for better ignitability of flame kernelRetains less heat, transfers heat to shell faster - reduces risk of pre-ignitionDyno testing has shown proven power gains
