NGK Iridium IX Spark Plugs are the key to ultimate performance. Specifically designed to suit the needs of the performance enthusiast, Iridium IX offers extreme ignitability, improved throttle response and superior anti-fouling properties. - Fine iridium tip ensures high durability and a consistently stable spark - Iridium alloy has extremely high melting point, perfect for today’s high-tech, high-performance engines - Trivalent metal plating provides superior anti-corrosion and anti-seizing properties - Outstanding acceleration, high fuel efficiency and durability - Ultimate design, technology and performance