The Spark Plug Serious Enthusiasts Rely On. Designed specifically for the performance enthusiast. Iridium IX® offers extreme ignitability, improved throttle response and superior anti-fouling. 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. Iridium alloy is extremely durable to heat, corrosion and electrical wear. Trivalent metal plating - superior anti-corrosion and anti-seizing properties. Outstanding acceleration, high fuel efficiency and durability. Ultimate design, technology and performance. 0.6 mm laser welded iridium tip. Tapered ground electrode to minimize "Quenching Effect". Sold individually. Plug model: CR8EIA-9.