The DigiFlow 8000T can monitor a single filter - flow volume or time elapsed. Users can program the flow volume and time by themselves. The DigiFlow 8000Twill count down from the programmed flow volume or time value, and generate an audible alert when it reaches the end. Besides this, the DigiFlow 8000T can display the REAL TIME flow rate. Two AAA alkaline batteries last for more than two years. The status is automatically memorized when the power is lost. It is designed mainly for residential and industrial water treatment applications. Features: Digital meter with ability to reset totalizing so users may track total flow in gallons. Offers ability to monitor five independent functions, with capacity settings from 100 to 9,900 gallons. (Stages that are not used can be disabled.) Audible alarm indicates cartridge replacement. Specifications: Range: 100 ~ 9900 Gallons 3/8" Pipe Thread (NPT) Port Recommended flow rate: 0.3 -2.0 Gallons per minute (GPM) Maximum flow rate capacity: 3.5 GPM Filter Life Monitor By Capacity and Elapse Time Real Time Flow Meter End of Filter Life Alert Large and Easy-to-read LCD Screen.