Champion REC10YC4 Marine Spark PlugChampion marine spark plugs are quality OEM replacements. The Champion REC10YC4 Spark Plug features a copper core electrode that provides increased conductivity and heat control for good overall wear. These marine spark plugs are designed to resist overheating under heavy engine loads. Dependable and durable; Copper core electrode allows for accurate control of heat range for longer life; Patented SAC-9 semiconductor for maximum EMI & RFI suppression.; Built to ISO and SAE standards for proven performance.Champion Spark Plug # 975