Fleck 5600 Metered Water Softener On Demand Control Head Valve Control head for water softeners. Fleck 5600 metered on demand valve Fits all standard tanks, 110 volt. 5 year warranty You will need a yoke connection or bypass valve for this if you do not currently have one This is metered meaning it will measure your water usage and regenerate as needed. Fleck is the most popular and reliable control valve for water softeners