MINI SIZE - The compact and portable size allows you to easily carry the pH meter in your pocket and take measurements anywhere. The pH meter can help you test the pH of water, whether you're taking it to the pool, on a trip, to the beach, or camping. ACCURATE TESTING - Using a high-sensitivity glass probe, this pH meter with a measuring range of 0 to 14.0 can quickly and easily read accurate pH values and perform precise tests within a pH range of ±0.01. The one-button reading lock function allows you to lock the reading even when the pH meter is removed from the sample. SELF-CALIBRATION - The digital pH meter is factory calibrated, but recalibration is necessary after long periods of inactivity or frequent use. pH 4.00/pH 6.86/pH 9.18 calibration powders are included. Press the pH meter's auto-calibration button to automatically identify calibration solutions. PHM METER - The pH meter has a multi-function function that can measure pH, TDS, and temperature with high accuracy simultaneously. The included detailed manual will show you how to obtain the best, most accurate, and stable readings. WIDELY USED - For home or laboratory use. The digital pH/TDS meter can be used to test drinking water, swimming pools, pH balance in aquariums, bathtubs, spas, wine, beer, and any other liquid, or anywhere it is necessary to test pH values and obtain accurate data.