Mercury 16951T1 | Brass Drain Plug for MerCruiser ManifoldsEngine block or manifold drain plug 16951T1 fits most MerCruiser sterndrive or inboard engines blocks and manifolds to make draining cooling water for winterizing or changing antifreeze easier. Can be used with engines equipped with closed cooler or raw water cooling systems. May also fit other brands of sterndrive or inboard engines and manifolds. See your owner's manual for installation instructions and application information.Fits MerCruiser cylinder blocks and exhaust manifoldsKey Product Features Easy to install with common tools; Replaces worn or damaged plugs to make winterizing your engine easier;