Features: 4 In 1 Detecting Function: This water quality tester can measure the PH, Total Dissolved SolidsTotal Dissolved Solids, EC, temperature and chlorine in water and help you fully understand the water quality of the tested water. Mobilephone APP Remote View: After connect with your mobilephone correctly through the BT, all testing results can be viewed on the APP. Large LCD Display Screen with Backlight: The large display screen with backlight allows you to read the testing data normally even in dim light or even in total dark, and you can turn on/off the backlight on your mobilephone. IP67 Waterproof: The IP67 waterproof level makes this product can be normally used in water and can provide a long service time. You can set a high or low PH/EC/TDS/ORP limit according to your needs, when the test results is above or below the range, the value be displayed in red to alarm you. Specifications: PH: Ranges: 0.1-14.0pH Resolution: 0.1pH Accuracy: ±0.1pH : Ranges: 0.1-4.0mg/L