Sea-Dog Inboard Motor FlushInboard Motor Flush Molded Rubber Aluminum Inboard Motor Flush quickly flushes away salt, sand, minerals, and contaminates from your lower unit cooling system extending the engines 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