NGK Laser Iridium Spark Plugs. Provide superior ignitability and long service life. Smallest tip diameter available, Iridium surfaces ensure slow wear rate providing stable idle, superior anti fouling, improved fuel efficiency and lower emissions. Features: Laser welded Iridium centre electrode tip; Platinum disc welded to backside of ground electrode provides long life; Trivalent Metal Plating for superior anti-corrosion and anti-seizing; Faster starts and quicker acceleration; Better fuel economy and lower emissions; Best OEM Iridium spark plug available; Original Equipment Manufacturer. Heat Grade 7. Perfect for Honda K-series K20A and Honda S2000 F20C engines. These are sold in a set of 4.