Smaller, more efficient, Iridium electrode designs are to improve cold starting and quicker acceleration. Designed to last over 100,000 miles in most applications. Require reduced ignition system voltage which increases lifespan of costly ignition system components. 100,000 mile limited warranty. OEM # Mercury# 33-884019001, Mercury 33-884019001, PCM/Crusader# RP030009, Volvo# 3858996 Box 4