Feature: 1. Equipped with a high‑sensitivity probe, rapid response, realize more accurate measurement. 2. Using LED digital display, the measurement result can be displayed intuitively, easy to operate. 3. 3 modes: temperature, calibration, locking, use automatic temperature compensation to reduce chip error. 4. Powered by large‑capacity button battery, low power consumption, stable performance and long service life. 5. Widely used in water purification systems, hydroponics, aquaculture, swimming pools, aquarium, etc. Specification: Condition: 100% Brand New 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. Package List: 1 x Water Quality Tester1 x English Manual Note: 1. Please allow 0‑2 cm error due to manual measurement. Thanks for your understanding.2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.