The WS1.5?? control valve has been re-designed to be more user-friendly for the installer and service technician in the field. This new design still uses all of the internal parts of its predecessor, so no need for additional or different internal repair parts. The relocated drain port to the top of the control allows the use of a wide variety of flow controls to be installed with ease. The high-efficiency brine system on the back of the valve is made from engineered composite plastic, and was developed for the WS1.5?? allowing it now to be used on systems up to a 30??-diameter tank with 15 cubic feet of softening resin. This new, powerful WS1.5?? valve now has flows of 65 gallons per minute for service and 55 gallons per minute for backwash. http://www.clackcorp.com, (608) 846-3010