Features: there are 2 kinds, with backlight/not, choose your own. OOTDTYM's pH Detector is designed specifically for fast and accurate performance. A newly developed high-precision multifunctional water quality tester that measures H2 and temp. It is very convenient to use, just insert the meter into the liquid to display the reading. Widely used in water quality testing, household drinking water testing, etc. Specification: Material: Plastic CaseSize: About 232(Length) X 80(Width) X 47(H) mm/9.1x3.1x2in Type: With Backlight/Not Power Supply: 3x Built-in Button CellC/F SwitchablePackage Included: 1x Water Quality TesterNote: Please allow 1-3cm error due to manual measurement. Pls make sure you don't mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item.