Autolite XST458DP Xtreme Start Iridium Lawn & Garden Spark Plug Designed for lawn and garden / outdoor power equipment applications 0.6mm iridium-enhanced finewire tip offers longer life and sustained performance Provides quicker consistent starts versus the average plug and an anti-foul design Finewire technology makes it easier to start, with a lower firing voltage required to fire the spark plug Proprietary nickel-chromium alloy side electrode for durability