Brass taps make draining manifolds easier Exhaust manifolds are equipped with drain plugs to remove excess water to reduce corrosion and possible freeze damage while being stored. The plastic and iron plugs supplied with most manifolds either become brittle or corrode due to constant heat cycling and exposure to salt and fresh water and can leak. Simple tool-less function can be restored by using metal drain taps. Sierra taps are made of bass to offer more durability and reduce the possibility of cross-threading that may lead to leaks. Each drain tap meets OEM specifications to ensure easy installation. Key Features Replaces plastic or cast iron plugs to add tool-less draining of manifolds Brass construction offers more corrosion resistance and stands up to heat cycling Engineered to match OEM specifications to ensure fit and function The Sierra Engine Parts Selector In addition to drain plugs, we offer a wide variety of other engine parts manufactured by Sierra. To see if we have the part you need, see ourEngine Parts Selector, where you can search by engine make, serial number and model or year of manufacture.ApplicationOEM Part NumberOEM Part NumberOEM Part NumberSierra Part Number18-421718-4218D18-4216GLM4501013993—Johnson/Evinrude Outboard—379957—Mallory—9-41201—MerCruiser Sterndrive—22-64426, 22-87238, 22-16951A1, 22-16951Q1, 22-16951T1, 22-16951T1—OMC Inboard—379957—OMC Sterndrive—379957—Volvo Penta8274482745807036