This optional valve (used in place of a pump) is designed to be installed in a pressurized water line and to be controlled by your CO2 monitor. This is a high quality solid brass valve designed for years of service. The valve has 3/4" NPT outlets that can be used to attach the valve inline with your existing plumbing or you can use the supplied ½" hose barbs to make the connection. You will need either a pump or a valve, but not both.