3-IN-1 MODE: This pH meter is designed in a 3-in-1 format for testing the quality of liquids such as drinking water, aquariums, swimming pools, spas, well water, and more. Ensure the safety of water in daily life. Please note that the pH meter shown in the video does not have a green backlight; the video is for reference only. Our pH meter features a green backlight. High Accuracy Tester: pH meter measuring range is 0.00–14.00 pH, resolution 0.01 pH, accuracy ±0.01 pH. TDS meter measurement range is 0–19999 ppm, resolution 1 ppm, accuracy ±2%. Thermometer measuring range is 0–60°C / 32–140°F, resolution 0.1°, accuracy ±0.5°C. Powerful Features: The pH tester supports automatic calibration at three points with 0.01 pH accuracy. No manual adjustment is required before use, making it convenient and ready to operate. The pH test pen includes automatic temperature compensation for more accurate readings. It also features an auto-off function after 5 minutes of inactivity to extend battery life and product longevity. Wide Application: Suitable for various liquid pH testing applications including drinking water, aquariums, swimming pools, school laboratories, food, beverages, reverse osmosis systems, hydroponics, and spas. After use, wipe the device dry with a clean cloth. Keeping the device dry helps prolong its lifespan.