?4 in 1? A very complete kit to check the quality of your water, whether it comes from the tap, from the recovery, from the aquarium or from a swimming pool. The TDS tester and the PH tester have a small size and light weight as a pen, they are easy to carry and allow you to take it in your pocket when you go out. ?Ease of use:? The TDS water tester locks the measurement result when you press the "HOLD" button and automatically turns off after several minutes of non-use. The pH tester has an automatic calibration function and you can quickly get a reading. And these 2-in-1 pH and TDS meters are also perfect for home or laboratory testing. ?High accuracy?: The numbers of the pH meter range from 0.00-14.00 (PH), while the numbers of the digital EC and TDS meters range from 0 to 19990 ppm. The PH resolution is 0.01 pH, accuracy 0.05 pH.TDS: 0 ~ 9990ppm, Conductivity: 0 ~ 9990us / cm, Accuracy: 2%, reliable and fast readings. ?Easy Calibration?: The pH tester automatically calibrates at three points (calibration only at 6.86 points: accuracy at 0.1 pH). You don't need any tools; just remove the protective cover and immerse the pH meter electrode into the solution. Press ON / OFF to open the electronic pH meter, stir it slightly and wait a few seconds until the readings are stable. ?Package Contents:? 1) A TDS-EC meter tester. 2) A pH tester with hard plastic storage 3) 3 pH calibration sachets. 4, Use instruction. A well-made kit with a clearly visible digital display. Eletorot portable PH, TDS and EC meters are professional multifunctional sets. They can be widely used for many water quality testing applications: pure water production and consumption, tap water, well water, sea water, aquarium water, swimming pool water, early rupture of amniotic fluid, etc.