Champion Iridium Plug Number RS12WMPB4 Spark Plug - 9405 Part #: 9405 Line: CHP Champion Iridium Plug Number RS12WMPB4 Spark Plug 2 Year LIMITED WARRANTY Seat: Tapered Thread Size: M14 Heat Range: 12 Hex Size (in): 5/8 Inch Preset Gap (in): 0.050 Inch Preset Gap (mm): 1.27mm Center Electrode Tip Material: Iridium Ground Electrode Tip Material: Platinum Service Number: RS12WMPB4 Metallurgy: Iridium/Platinum Show More Show Less