Champion QL77JC4 Spark Plug, 0.028 to 0.033 in Fill Gap, 0.551 in Thread, 0.813 in Hex, Copper

High voltage semi-conductor resistor for maximum EMI suppression. Copper core center electrode reduces engine misfire caused by fouling. Triple seal assembly with upper and lower metal gaskets and sillment seal, eliminates spark plug failure due to heat or mechanically induced stress. Triple coated shell, Tintac and Ultraseal over zinc plating resist corrosion and spark plug seizure.