NGK (4929) DPR8EA-9 Standard Spark Plug, Pack of 1 Solid copper core for greater spark Longer insulator nose prevents fouling Corrugated ribs on insulator prevents flashover Zinc dipped shell prevents corrosion Triple gasket seal eliminates combustion gas leakage Solid copper core for greater spark Corrugated ribs on insulator prevents flashover Zinc dipped shell prevents corrosion Triple gasket seal eliminates combustion gas leakage