Feature 1、PREMIUM MATERIAL: Water quality tester is made of ABS premium material, wear resistant and sturdy. Battery cover with sealing gasket design, waterproof sealing, strong and reliable. 2、SENSITIVE PROBE: Digital water quality tester has a high sensitivity electrode probe, high precision water quality measurement, automatic temperature compensation, reduce errors. 3、LARGE LCD SCREEN: HD LCD screen, large screen display, the value is clear and easy to read. Mode memory function, each time the default mode for the last use of the mode before power off. 4、MODE SWITCHING: Water quality test pen has 4 different modes, ORP, CL₂, H₂ and TEMP can be switched to different modes by pressing the key. Digital screen helps you see the measurement clearly in any situation. 5、BUTTON OPERATION: Press HOLD/TEMP to save the current test range, press and hold to change °C/°F, press MODE/CAL to change the test mode, press and hold to calibrate the test value. Item Type: Water Quality Tester Detection Range: ORP, CL₂, H₂, Temperature Material: ABS Length: Approx. 186mm/7.3in Gross Weight: 130g/4.6oz Applicable Industries: Swimming Pools, Hot Springs SPA Places, Water Plant Laboratory, Aquaculture Industry, Food Processing Plants, Other Battery (Shipped Without Battery): 3 x LR44 Button Cell Batteries Waterproof Grade: IP65 Working Environment: 0‑60℃(32.0‑140.0℉), RH:100% Backlight: LCD Backlit Display Automation Off: 5 Minutes Display Mode: LCD Digital Display Calibration Mode: Automatic Calibration ORP: Measuring Range: ±1999mV Resolution: 1mV Accuracy: ±2mV H₂ (Hydrogen Rich): Measuring Range: 0‑10000ppb (0.001‑10.000ppb) Resolution: 2ppb (0.002ppb) Accuracy: ±10ppb, (±0.01ppb) Temperature Compensation: (0~60)℃ (automatic) CL₂: Measuring Range: 0.01~4.00ppm (Total Residual Chlorine) Resolution: 0.01ppm Accuracy: ±10% of Reading Value, ±0.01ppm Temperature Compensation: (0~60)℃ (automatic) TEMP (Temperature): Measuring Range: 0‑60℃ Resolution: 0.1℃ Accuracy: ±0.1℃ Package List 1 x Water Quality Tester 1 x Instruction Manual 1 x ORP Test Kit Note Maintenance: Shake off the water after the test, keep the motor clean, if not used for a long time, please take out the battery, cover the electrode protective sleeve.