Fleck 9000 and 9100 Twin Alternating Control Valves are a perfect choice for Residential or Light Commercial application where continuous supply of soft water is needed 24/7. Non-corrosion and UV-resistance Fleck 9000 & 9100 twin tank system are made of a fiber reinforced polymer valve body for superior strength and durability. The Flack 9000 and 9100 Control Valves are designed for a service flow rate of 20 GPM with a backwash of 8.5 GPM.