Compare Maximum number of 4 items selected Autolite Iridium Ultra Spark Plug - AI3924 Part #: AI3924 Line: ATO Autolite Iridium Ultra Spark Plug Limited Lifetime Warranty Seat: Gasket Thread Size: M14-1.25 Heat Range: 9 Hex Size (mm): 16mm Hex Size (in): 5/8 Inch Preset Gap (in): 0.044 Inch Preset Gap (mm): 1.1mm Thread Reach (in): 0.750 Inch Resistor Plug: Yes Center Electrode Core Material: Copper Center Electrode Tip Material: Iridium Approximate Resistor Value (Ohm): 4000 Ohm Insulator Height (mm): 51mm Insulator Height (in): 2.007 Inch Ground Electrode Tip Material: Platinum Thread Reach (mm): 19mm Metallurgy: Iridium/Platinum Show More Show Less