AC Delco MR43T Iridium Spark PlugThis AC Delco spark plug iridium construction provides outstanding strength and high temperature resistance. Made with nickel alloy tip, copper core and ribbed suppressor seal for durability and performance, 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 MR43T Interchange Mercury 33-8M0204752; Donovon 203276; NGK BR6FS; Using the latest in spark plug technology AC Delco is a trusted brand that will provide quick start ups when it matters most.