Usage Tips:3-IN-1 MODE: This pH meter is designed in 3-in-1 format for testing the quality of liquids such as drinking water, aquariums, swimming pools, spas, etc. #39;well water, etc. Ensure the safety of water in daily life.Please note that the PH meter in the video has no Green Backlight, which is only for reference for re-reading the PH meter. Our PH meter is with Green Backlight. High Accuracy Tester: PH meter: Measuring range is 0.00-14.00 PH; The resolution is 0.01 pH; Accuracy is 0.01pH. TDS meter: The measurement range is 0-19999ppm; Resolution 1ppm; Accuracy is 2%. Thermometer: The measuring range is 0-60C/32-140F, The resolution 0.1; Accuracy is 0.5C Powerful: pH tester is able to automatically calibrate at three points (accuracy is 0.01ph). No adjustment needed before use. It is very convenient to use. The pH test pen also has an automatic temperature compensation function, which allows you to obtain more accurate test values. At the same time, it will automatically turn off when you haven't used it for 5 minutes, thus extending the service life of the product. Wide Application: The pH meter is suitable for various pH liquid tests, such as drinking water, fishing, aquariums, swimming pools, school laboratories, food, beverages, reverse osmosis systems, hydroponics and SPA. After use, please wipe off the water on the device with a clean cloth. Keeping equipment dry can extend its life.