Autolite Xtreme Performance Iridium Spark Plugs are technologically advanced with an iridium-enhanced 0.6 mm fine wire design and proprietary platinum side wire technology working to provide better durability and a more focused ignition for better overall ignitability and optimum performance. These premium spark plugs also feature an iridium-enhanced center electrode and nickel-plated shell. Guaranteed for 7 years.