AC Delco 41-110 Iridium Spark PlugThis AC Delco spark plug iridium construction provides outstanding strength and high temperature resistance. Iridium offers better engine idle stability, quick acceleration, and smooth engine performance.Benefits of AC Delco Spark Plugs Iridium Construction; High Melting Point; Laswer-Welded; Reliable Cold Starting; AC Delco 41-110 Interchange Donovan 203054; NGK IZTR5B11; Using the latest in spark plug technology AC Delco is a trusted brand that will provide quick start ups when it matters most.