• High precision pH tester: The glass probe of this pH tester is made of a low resistance glass sensitive film (25 MQ) and the response speed is 0.1 seconds. The TDS electrode is a high-quality titanium alloy sensitive probe with high precision to ensure accurate readings. The mini-sized meter we have designed allows you to easily put it in your pocket, so you can take measurements anytime, anywhere. • 5 in 1 Multifunction: This digital pH meter is designed with 5 in 1 function, which can be used to test PH/TDS/EC/salinity/water temperature. The measurement range is pH 0.00-14.00 (accuracy 0.01PH), TDS 0-10,000 ppm, 10.1-200.00 ppt, EC 0-10,000 uS/cm, 10.1-19.99 mS, 20.1-400.0 mS/cm, salinity 0.01%-25.00% and temperature 0-60 ℃. • High quality material: This water quality pen is made of high-quality ABS, IP65 waterproof, full protection, no need to worry about water entering the machine (for accurate data, do not immerse the water quality pen in water). This product requires 3 LR44 batteries (not included, please bring your own). Easy to use: turn on the switch, place the probe in the water and stir, and the value can be read when the value is stable.