ACDelco 41-818 Professional Platinum Spark Plug, Pack of 1 One-piece, fired-in suppressor seal blends three glass types for a gas-tight seal reducing radio frequency and engine interference and regulating spark plug energy and seals against compression pressures for long life Dual platinum point pad on center and ground electrode offer increased durability and consistent voltage demands to reduce wear on ignition system 100% pure copper core results in cooler electrode temperature for enhanced durability and superior fouling resistance