AC Delco 41-963 Iridium Spark PlugThis AC Delco spark plug iridium construction provides outstanding strength and high temperature resistance. Iridium fine-wire electrode helps improve ignition of the fuel and burns away carbon deposits on the tip of the plug as they form, to help improve fuel economy. Iridium offers reliable cold starting, quick acceleration, and smooth engine performance.Benefits of AC Delco Spark Plugs Iridium Construction; High Melting Point; Laswer-Welded; Reliable Cold Starting; AC Delco 41-963 Interchange Donovan 203050; NGK PTR4G-15; NGK ITR4A15; Using the latest in spark plug technology AC Delco is a trusted brand that will provide quick start ups when it matters most.