Note, this is for filter tank systems, not water softeners. If you need a replacement valve for a water softener, see our other listings. *Features Fully adjustable controls. Time-tested, hydraulically-balanced piston, seal and spacer, controls service ? ow and regeneration Non-corrosive, ? ber-reinforced polymer construction Excellent ? ow rates (19 GPM continuous, 24 GPM peak) Backwash capacity handles tanks up to 16" diameter ---- -- This is a valve for use on a water softener system. Does not include bypass valve. If you also need a new bypass valve, see our other listings for that part. Will ship with standard flow control set at 7 gpm which will be appropriate for most all applications, unless you email us at time of order with request for other size dlfc.-- Standard 1" distributor pilot. If you need a bypass valve to fit on this head, see our other listings.