" A very practical complete kit to check the quality of your water, whether it comes from the tap, the recovery, the aquarium or a swimming pool. The TDS tester and the PH tester have a small size and low weight as a pen, they are easy to carry and allow you to take it in your pocket when you go out. This 2-in-1 pH and TDS Meter Kit is ideal for home or lab testing. 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 feature and you can quickly get a reading. Easy Calibration: The pH tester automatically calibrates at three points (6.86 and 4.01 point calibration). You don't need any tools, just immerse the pH meter electrode in the solution. Press " ON / OFF " to open the pH meter electronic, shake it lightly and wait a few seconds until the readings are stable. Widely Used: Suitable for testing drinking water, swimming pool, aquarium, spa or hydroponics. You can calibrate the tester with a touch button using buffer powder. Please make sure there is no water in the PH meter & amp; TDS after use, otherwise they will rust. Package Included: 1) A TDS-EC Meter Tester. 2) A pH tester with hard plastic storage 3) 3 pH calibration bags. 4, use the instruction. A well-made kit with a clearly visible digital display. "