NGK - Standard Spark Plug - LFR6A-11 (3672) - 12 Pack. Handle your next tune-up with confidence using the NGK LFR6A-11 standard spark plug in a 12 pack. NGK standard plugs are selected by more automotive, motorcycle, and marine engine manufacturers than any other. A proven copper core and precision electrode design help support fast starts, steady ignition performance, and dependable service life.. This 12 pack is ideal for multi-cylinder engines or keeping extras on hand so you are ready when routine maintenance comes due.. Key Features. Plug Number: LFR6A-11. NGK Part Number: 3672. Pack Size: 12. Unique copper core and electrode design for fast starts, strong performance, and long life. Triple gasket sealing process helps eliminate gas leakage past the shell. 99% highly pure alumina silicate insulator for strength and heat resistance. Solid copper core supports efficient heat transfer and durability. Corrugated ribs help prevent flash over. Cold rolled threads help prevent damage to