Feature: 1. With Relay Output Power Socket: pH can be controlled as required. You can easily and quickly replace the fuse with external replacement. Removable and replaceable pH electrodes. 2. With Power Plug: For use with gas stones, oxygen pumps, carbon dioxide regulators, solenoid valves and other pH control devices. 3. Calibration: Feel free to test EC in us/cm and ms/cm units. pH EC can be easily calibrated with just a mini screwdriver and automatic temperature compensation. 4. Clear LCD With Backlight: Easy to use and provides immediate display of results. Test temperature °C °F (switchable unit), long term online monitoring and control of pH value. 5. Multipurpose: Used to test the pH, temperature, EC (conductivity) of water, suitable for swimming pools, aquariums, soilless cultivation, laboratory, environmental water. Specification: Item Type: PH Meter Material: ABS Scope: PH: 0.00-14.00PH EC: 0-1999us/cm ms0-19.99ms/cm Temperature: -50℃-70℃ (-58℉-158℉) Resolution: PH: 0.01PH EC: 1us/cm ms0.01ms/cm Temperature: 0.1°C (0.2°F) Accuracy: PH: ±0.1PH EC: ±2%F.S Temperature: ±1.0°C (±2°F) Alarm Setting Range: PH 3.50PH-10.50PH Weight: Approx.1013g / 35.7oz. Package List: 1 x Water Quality Tester1 x PH Electrode1 x Temperature Electrode2 x Suction Cup1 x Screwdriver1 x User Manual4 x Screw4 x Expansion Plug