Splitfire, Inc. SF2C Resistor Spark Plug Split "V" Ground Electrode Nickel Spark Plug 14mm Thread, 11.6mm (.460") Reach, 5/8" (16mm) Hex Size, Tapered Seat, Resistor, Solid Terminal, Power Tip, Copper Core, Split "V" Ground Electrode Sample Image Provided May Differ From Actual Product.