This reducer is designed for the introduction of water from the dock to the onboard system. The connection to the dock water pipe is made via a snap fitting of the gardening type (see code 36.189.02), while the output is equipped with a 3/4" male thread. Pressure reducers with a plastic element, like this one, do not reduce pressure but limit flow rate. This allows water to enter the system gradually, avoiding stress on the piping. If the system remains connected to the dock, the pressure automatically aligns with that of land.