The Milwaukee C66 Waterproof Conductivity Tester has an IP67 waterproof housing and is specially designed for the hydroponic and agricultural markets. The meter has automatic temperature compensation and 1 point manual calibration. The C66 has a range of 0.00 to 10.00 mS / cm, has a replaceable electrode and comes with calibration solution sachets (M10031) and a screwdriver for calibration. The modular design makes it easy to replace the electrode and battery.