Flush your inboard engine safely and easily with the FlushPro from Perko. This durable check valve system is activated by water pressure from a garden hose. The check valve automatically shuts off hull intake when water pressure is applied. The transparent body allows visual inspection of water flow. The supplied adapter makes winterizing your boat easy. Can be used with onboard generators. Transparent body for inspection of water flow Can be used with onboard generators | Perko Flush Pro, 1" inlet