A convenient way to protect exhaust system components. Exhaust elbows can retain raw cooling water that can promote internal corrosion and possibly freeze in the winter. Having a quick means to drain this trapped water can extend the life of exhaust system components. This stainless steel Sierra drain is engineered to thread into 3/4" NPT ports found on MerCruiser exhaust risers, elbows and manifolds and provides a way to quickly remove captured water. For a convenient way to protect your engines exhaust system, install a Sierra elbow drain. Key Features Stainless steel construction resists corrosion Provides quick way to drain exhaust system water to reduce corrosion and freeze damage risks Compatible with MCM/MIE V-6 & V-8 engines with center rise exhaust manifolds Backed by SeaStar Solutions Limited Two-Year Warranty 18-4224D Application Guide ApplicationOEM Part NumberGLM13990Mallory9-41200MerCruiser Sterndrive22-806926A1, 22-862210A01The Sierra Engine Parts SelectorIn addition to elbow drains, 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.