Five Oceans Universal Outboard Motor Flusher, Rectangular, Round and Dual Flow Rectangular BEST USE for Engine Flushing Winterizing. UNIVERSAL FLUSHER compatible with Outboards Sterndrives CLAMP over water intake then flush outboard with a garden hose DIMENSIONS - (Round Muffs): 3 5/8" (92mm) FLUSH your engine after every trip with this easy to use motor flusher, it also comes with Hose Adapter. EXTEND your outboard engines life by regularly flushing out salt, silt and grime