Fleck 2510 SXT AIO 3 Cycle, Timer Clock Backwashing Filter Valve, No DLFCPentair Fleck 2510 SXT AIO Timer Control Valve Automated air injection backwashing valve for whole house iron, sulfur, and manganese filtration no chemical feed or external air tank required 2510 AIO Platform 1" FNPT Ports 12 GPM Service Flow 12 Day Timer Clock The Fleck 2510 SXT AIO is a timed backwashing filter control head that integrates air injection directly into the valve body, eliminating the need for separate aeration equipment or chemical