Usage: Help you drink the safe and pure water, protect your health. Check the performance of your water filter and the hardness of the water you drink (1 grain =17 ppm). Dual Range : Measures form 0-999ppm, with a resolution of 1ppm. From 1,000 to 9,990ppm, the resolution is 10ppm, indicated by drinking x 10image, +/- 2% High Accuracy Features: The meter can lock the readings to help you read and record. Turns off meter after 10 minutes of non-use to save batteries Easy to Carry:The testers is lightweight ,rasy to storage and portable.It fit in your pocket and you can take it anywhere. Please note: This meter CANNOT calibrate, It can be used in : water purifiers and filters, food (vegetable, fruits) drink quality monitoring, pools and spas, aquariums, hydroponics. 1. Ability to lock detection data 2. Able to automatically shut down 3. The unique temperature compensation function can be automatically converted into the TDS value at a water temperature of 25 degrees Celsius 4. Large-screen LCD display waterproof design, easy to watch and durable Power supply: 2 x 1.5V button batteries (included) Dimensions: 15.5 x 3.1 x 2.3 cm Note: It does not include other things, the color is based on the first picture, and the other pictures only show the effect Due to the differences between different monitors, the picture may not reflect the actual color of the item. We guarantee that the style is the same as the picture. Due to manual measurement. Please allow deviation. Thanks!