Features: 1.With lock function, convenient to read and record, instrument will lock the reading. 2.Easy to operate, convenient to carry, can test whether the fish tanks water pollution or too hard, timely detection of the water quality of the fish tanks environment. 3.Can also used to test the drinking water of livestock on farms, to reduce feeding problem caused by livestock get sick or water quality. 4.The instrument has function of automatic temperature compensation under the measuring mode. 5.Temperature switching, light touching SHIFT key 2 times continuous, Celsius and Fahrenheit switching, instrument factory default Celsius. 6.Maintaining, keep the electrode clean and cover the electrode protective cover, if it is not used for a long time, please take out the battery. Specification: Item Type: Water Quality Testing Pen Material: Plastic + Titanium Alloy Color: As Picture Shown Battery Model Quantity: CR2032*1(Not Included) TDS Measurement Range: 0-9990PPm Conductivity Measurement Range: 0-9990us/cm Temperature Measurement Range: 0-80℃ Accuracy: ±2% Weight: Approx. 54g Using method: Before using, please unplug the electrode protective cover; press the key to put the electrode into the solution to be measured; when the value is stable, press the HOLD key to take out the reading; after reading, press the key to turn the electrode wipe clean, just put the electrode protection sleeve into it. PackageList: 1 x Water Quality Testing Pen1 x Manual Note： The value showing PPM unit is TDS value, the value showing us/cm unit is conductivity value, TDS value and conductivity value lightly press Shift key to switching.