[ Convenience Use ] 5 Seconds know water quality, Accuracy, Faster. This set Combo of TDS PH EC Temperature. Also it have Best Price, Trustable Quality, all make it be your FIRST water quality Test. [ How Accuracy? ] PH resolution is 0.01pH,accuracy 0.01pH.TDS:0~9990ppm,Conducitivity:0~9990us/cm,Accuracy:2%. [ Lasted Model ] PH pen have AUTO CALIBRATION function, not need any kind of screwdrivers to calibrate the pH pen tester.TDS pen have Lock & auto shut off function. [ Pocket Portable ] Small size but Suitable for testing pH balance of drinking water, pool, aquarium, RO system, Spa, or hydroponics. [ Wide Application ] Ideal for Home and Laboratory PH Testing, Including Drinking Water, Electroplating Liquid, Boiler Water, Water in Fish Tank, Water of Swimming Pools, Photograph Flushing Fluid, Well Water, Deep Phreatic Water, Aquaculture, Food Processing and More. [Battery]3VCR2032 button battery/LR44 button battery [size]155*31*18mm/155*14*30mm [quantity]2pcblue ph meter + white tds&ec pen