FunctionThe LCD digital TDS tester is used to test the purity of the filter water to check the performance of the water. To ensure you always drink pure and safe water, it is recommended to use a TDS meter tester for each home. Wide Range of Applications This product can be used for monitoring the water quality of water purifiers and filters, food (vegetables, fruits) and beverages, swimming pools and spas, aquariums, hydroponics, etc. Auto Power Off Function After 10 minutes of inactivity, the meter will turn off to save battery power and ensure long-term use. Hold Function This water quality detector saves the measurement results for easy reading and recording. Measuring Range 0-9990ppm Specifications: Condition: Brand New Shell Material: Plastic Main Color: Yellow Range: 0~9990ppm Accuracy: +/- 2% Battery: 2 x CR2032 1.5V Button Batteries (Not Included) Size: Approx. 15.5 x 3 x 1.6 cm / 6.1 x 1.1 x 0.6 in Package Included: 1 x Water Quality Tester (Without Battery) Note: 1. Please allow 0~1inch 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.