NGK Laser Iridium spark plugs provide superior ignitability and long service life.; Fine wire iridium tipped center electrode and fine wire platinum tipped ground electrode ensures slow wear rate providing stable idle, superior protection against fouling, improved fuel efficiency and lower emissions.; IMR9C-9HES Spark plug Fine wire Iridium center electrode Platinum vibration resistant ground electrode Copper core helps dissipate heat from cylinder head Pure alumina silicate ceramic insulator, provides superior strength and improved heat transfer Triple seals prevent leakage 100,000 mile service life