ACDelco 41-985 Professional Iridium Spark Plug, Pack of 1 Smaller, more efficient, Iridium electrode designs are to improve cold starting, quicker acceleration, and lifespan Designed to last over 100,000 miles in most applications ACDelco Iridium plugs require reduced ignition system voltage which increases lifespan of costly ignition system components 12-month/12,000-Mile Limited Warranty ACDelco is an Original Equipment (OE) supplier and has the experience engineering and manufacturing components that achieve the highest quality standards required by vehicle manufacturers