The LCD digital TDS meter tester is used for testing the filter water quality purity, to check the performance of your water. In order to make sure you always drink pure and safe water, the TDS meter tester is recommended for every family. Features: 1. The TDS meter tester can be used in: water purifiers and filters, food (vegetable, fruits) & drink quality monitoring, pools and spas, aquariums, hydroponics etc. 2. Hold function: Saves measurements for convenient reading and recording. 3. Auto-off function: Turns off meter after 10 minutes of non-use to conserve batteries. 4. Press "TEMP" button can shift temperature meter between fahrenheit degree and centigrade degree. 5. Measures Range: 0-9990ppm, with a resolution of 1ppm. From 1,000 to 9,990ppm, the resolution is 10ppm, indicated by drinking x 10image, factory calibrated. 6. Applicable industries: water laboratories, CDC, the aquaculture industry, hospitals, swimming pools, household tap water quality testing. Specification: Condition: 100% Brand New Shell Material: Plastic Main Color: Red Range: 0~9990ppm Accuracy: +/-2% Battery: 2 x 1.5V LR44 Button Cell Batteries (not included) Size: 15.5 x 3 x 1.6cm / 6.1 x 1.1 x 0.6 inch (appr.) Please refer below standard for testing water 0~50ppm --------- High Purity Water 50~100ppm --------- Pure Water 100~300ppm --------- General Pure Water 300~600ppm --------- The water will have incrustation scale 600~1000ppm --------- Bad Taste Water Above 1000ppm --------- The water is not suitable for drinking Package List: 1 x Water Quality Tester (Not include the 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. .