4-in-1 PH Tester: A very complete kit to check the quality of your water, from the tap to the treatment, including the aquarium or swimming pool. TDS/PH testers have small dimensions and light weight like a pen, pH meter for drinking water, beverages, for aquariums, hydroponics, swimming pools. Ease of use of pH meter: TDS water freezes the measurement result when you press the "HOLD" button and turns off automatically after a few minutes of non-use. And these 2-in-1 pH meters and TDS meters are also ideal for home testing. High accuracy: The pH meter numbers range from 0.00 to 14.00 (PH), while the digital EC and TDS meter numbers range from 0 to 19,990 ppm. Use a digital meter to get precise numbers instead of comparing the color with pH test paper. Avoid inaccuracies due to different light. It is also useful for people with low color. < p>Easy Calibration: The pH tester automatically calibrates to three points (6.86 and 4.01 point calibration). No tools are needed, just immerse the