Simultaneously monitors and controls the TDS levels of two water lines (e.g., the feed water and product water) for high output commercial systems. Large, bright LED displays. An alarm sounds if TDS level rises above user-set level for either line. Installs easily in minutes. Includes two 1/2" sensor probes. Range: 0 - 999ppm; Accuracy: ±2; Resolution: 1 PPM; ATC: Yes (1 - 65 degrees Celsius); Calibration: Adjustable; Setting: Controlled by on-screen up/down buttons; Relay Control: The unit will transmit an analog signal to a pump/valve when the ppm levels reach or exceed the control settings for either line (simple switch). Relay Voltage: 5V; Alarm: steady beep for both lines Display: Bright 5/8" LED dual displays; 2 Probes: 1/2" bushing, 9.8 ft. shielded cable; Power supply: AC 110V / AC 220V; Dimensions: 3.7 x 3.7 x 4.9 in.; Monitor weight: 1 lb 4.1 oz; Total weight: 2 lbs 1.1 oz.