?4 in 1? A very complete kit to check the quality of your water, whether it comes from the tap, the recovery, the aquarium or a swimming pool. TDS tester and PH tester are small in size and light in weight as a pen, easy to carry and easy to take 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 get a reading quickly. And these 2-in-1 pH and TDS meters are also perfect for home or lab testing. High Accuracy: The numbers of the pH meter range from 0.00-14.00 (PH ), while the numbers of the EC and TDS digital meters range from 0 to 19990 ppm. PH resolution is 0.01pH, Accuracy 0.05pH.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; simply 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. ?Package contents:? 1) A TDS-EC meter tester. 2) A pH tester with hard plastic storage 3) 3 pH calibration pouches. 4, use instruction. A well-made kit with a clearly visible digital display. Eletorot portable PH, TDS and EC meters are multifunctional professional sets. they can be widely used for many water quality testing applications: production and consumption of pure water, tap water, well water, sea water, aquarium water, water swimming pool, early rupture of amniotic fluid, etc.