Best used as a spare part, or to ensure your kayak does not get damaged by hot expanding air while in a hot sand beach. Sometimes called the Over Pressure Relief Valve (aka Safety Relief Valve). Use a Push-Push Valve Wrench for install and removal.
Valve is approximately 2 1/6 inches in diameter. The photo above shows valve open. The photo to the right shows the valve closed. You are purchasing One Single Valve. (2020 part number 043992)