Simple but effective solution to prevent backflow. Scuppers are a great way to clear unwanted water off the deck or cockpit sole, but left open they can be a source of unwanted water as the boat backs down or in following seas. Our scupper valve is a quick and simple way to prevent water from entering through the scuppers. This one-way flap surfaces mounts to the exterior of the transom and closes shut with the pressure of water pressing against the scuppers/