4 in 1 set very complete set" to monitor the quality of water, whether it is tap water, reclaimed water, aquarium or swimming pool. The TDS digital device is as small and light as a pen. It's easy to carry and store when you go out in your pocket.Ease of use: The TDS TDS water tester freezes the measurement when you press the "HOLD" button and automatically shuts off after a few minutes of inactivity -The instrument has an automatic calibration function, you can get a quick reading . Product Description Multifunctional Professional Coverall It can be widely used in a variety of water quality testing applications : production and consumption of pure water, tap water, well water, sea water, aquarium water, swimming pool water, early water degradation, amniotic fluid, etc. 3-in-1 EC TDS Thermometer Upgrade to a large LCD display for easier reading Features Sensitive electrode sensor has a measuring range of 0.00 to 14 .00 pH. One Touch Calibration Instrument (CAL) Large screen, data is clearer than before. Note: The data is all manual measurement, please allow 1-3cm error, due to the difference in light and display, there will be a certain color difference, depending on the physical object received Delivery quantity: (according to the main image)