Champion Marine Spark Plug UL77V #831 #831M Purchase is for one plug. Plug may be card or box. The spark plug is designed to withstand high temperatures and fits most small-engine brands and models. ? For use with small marine engines ? Champion copper plus small engine plugs resist fouling and provide superior corrosion resistance ? Feature a copper core electrode that provides increased conductivity and heat control while delivering good overall wear characteristics ? Semiconductor suppressor: Eliminates radio frequency interference ? Engineered to exceed OE designs and maximum durability ? Designed for easy starting ? Plug Type: UL77V Seat Type: Gasket Hex Size: 13/16 Inch (20 mm) Thread Size: 14 mm Plug Reach: 0.531 in (13.5 mm) Preset gap: 0.048 to 0.053 in MPN: 831, 831M UPC card: 03755156564 UPC box 1 plug: 037551005147 USA domestic shipments are shipped USPS First Class Mail with Tracking International shipments are shipped USPS First Class International Mail with Tracking