NGK 6993 Spark Plug Set Spark Plugs: Buy Spark Plugs In Automotive At Copper Core Spark Plug 4 Pack The unique copper core and exclusive electrode design assure fast starts peak performance and long life. NGK BKR6EKU - Alternatve spark plugs Triple gasket sealing process eliminates gas leakage past the shell 99% Highly pure alumina silicate insulator Solid copper core Corrugated ribs to prevent flash over Cold rolled threads to prevent damage to cylinder head Trivalent plating - silver chromate and zinc for corrosion resistance Sold in standard packs only Model #: BKR6EKU Pack: 4 Pkg., : Boxed Add this item to the Shopping Cart to see your reduced price.Product Description: NGK Spark Plugs, BKR6EKU #6993 4/Pack Standard spark plugs are chosen by more automotive, motorcycle and marine engine manufacturers than any other Standard spark plugs are chosen by more automotive motorcycle and marine engine manufacturers than any other. Yamaha Outboard Spark Plug Chart ( Gap & Socket Size Product Type - SPARK PLUG