Aftermarket DRAIN PLUG ASSEMBLY For Mercruiser Exhaust Manifold Replaces Part Numbers 13992; 18-4226; 22-806608A1 AFTERMARKET Mercury Mercruiser Closed Cooling Drain Plug & O-Ring Fits most Mercruiser marine engines. Replaces: 22-806608A1 and 22-806608A02 Replaces: 18-4226 and 13992 Free Shipping