4-in-1: This tester kit can help you test pH, water quality, temperature and EC within 5 seconds, to ensure that you always drink pure water. And these 2-in-1 pH Meter TDS Meter are also great for home or lab testing. Accurate and Reliable: pH meter: Measuring range is 0.00 - 14.00pH; The resolution is 0.01 pH; Accuracy is 0.01 pH. TDS meter: The measuring range is 0-9999ppm; Accuracy is 2% FS Auto Calibration: The pH Tester automatically calibrates at three points (calibration only at 6.86 points: accuracy at 0.1 pH). You dont need any tools; just remove the protective cover and immerse the pH meter electrode in the solution. Press ON/OFF to open the electronic pH meter, shake it slightly and wait a few seconds until the readings are stable. LCD display backlight: The pH meter and The TDS meter adopt LCD screen backlight to make data display clearer. Even if in a dark environment, you can easily view the data. When not in use, it will automatically turn off after 5 minutes to save battery power. Lightweight and portable design is for comfort and portability. Wide Usage: The pH meter is suitable for various liquid pH tests, such as drinking water, fishing, aquariums, swimming pools, school laboratories, food, beverages, reverse osmosis systems, hydroponics and SPA.