The Watts A200 features a unique new design that assures delivery of water to the trap to prevent the evaporation of the water seal. The design allows for a complete flow cycle through the valve from open to close that will actuate the primer twice with two definite pulses-once on opening and once on closing-thus providing a tremendous water savings over competitive models. The A200 also features a built-in air gap and is available in both threaded and solder ends.Watts Regulator Co. Circle 12.