Flush saltwater, silt and other contaminates from smaller Mercury outboards. After running in saltwater or through silty water, it is good idea to flush the engines cooling system to remove debris and corrosive saltwater. This flushing kit is designed to work with 4hp- 15hp Mercury outboards to run freshwater through the cooling system at idle. A coated metal bracket holds a rubber cup to the side raw water intake opening which provides a garden hose connection for freshwater supply. Position the cup over the intake, turn the water on, and start the engine to flush the cooling system. Key Features Allows engine to be run at idle out of the water to remove debris and saltwater Flushing reduces adverse effects of particulate and saltwater contamination Designed to work with Mercury outboards 2004 and older 4-15hp 2-cycle; 2004 and older Mercury Mariner 9.9 and 15hp 4-stroke outboards with standard gear case; 2005 Big Foot 4-stroke