1Equipped with a highsensitivity probe, rapid response, realize more accurate measurement. 2Using LED digital display, the measurement result can be displayed intuitively, easy to operate. 33 modes: temperature, calibration, locking, use automatic temperature compensation to reduce chip error. 4Powered by largecapacity button battery, low power consumption, stable performance and long service life. 5Widely used in water purification systems, hydroponics, aquaculture, swimming pools, aquarium, etc. Condition: Item Type: Water Quality Tester Material: Plastic Model: ORP-100 Measuring Range: -1200 - 1200MV Measurement Accuracy: +-2mv Resolution: 1mv Temperature Compensation: Automatic Temperature Compensation (ATC) Calibration: 7 Seconds Built-In Automatic Calibration Accuracy: TEMP+-0.5 Resolution: TEMP: 0.1 Power Supply Mode: 3x1.5V (LR44) Standby: Automatic Shutdown in 10 Minutes Lock: Manual Key Lock Battery: 3 x LR44 Button Battery 160mAh Product Size: Approx. 187x37x37mm / 7.4x1.5x1.5in 1 x Water Quality Tester 1 x English Manual 1.Pleaseallow0& 8209;2cmerrorduetomanualmeasurement.Thanksforyourunderstanding.2.Monitorsarenotcalibratedsame,itemcolordisplayedinphotosmaybeshowingslightlydifferentfromtherealobject.Pleasetaketherealoneasstandard.