Inboard Motor FlushMolded Rubber/Aluminum Inboard Motor Flush quickly flushes away salt, sand, minerals, and contaminates from your lower unit cooling system extending the engine’s service life. Easy-to-use by fitting the rubber cup over the water intake, connecting a garden hose, and extending the aluminum leg to seal the cup to the hull. Fresh water flushes the cooling system, no tools required. Great for winterizing, tune-ups, and other maintenance that requires running an inboard engine out of the water.