Waterproof Design---Completely waterproof design, suitable for trial in various environments, with full temperature compensation function High Performance---The flashing LED light scale provides you with all the information you need; the automatic opening and closing function activates the baton when it is put in or removed from the solution. There are no external knobs or switches Accurate Readings---The accurate readings of the baton at each time are factory calibrated (the EC 1.4 buffer solution can be used to easily perform further calibration on a regular basis to maintain accuracy). High conductivity measurement, suitable for a variety of crops Easy to Use---Just put the head of the probe into the solution for 1-2 minutes to make the temperature of the probe and the liquid the same. Then remove the probe and put it back into the solution. LED lights will indicate the nutritional level Ideal Tool---If you use hydroponics to grow your own fruits and vegetables, you will know that the correct intake of nutrient mixtures is very important. Measure EC (conductivity), CF (conductivity) and PPM (parts per million) scale