The Milwaukee Mi805 measures 4 parameters with 1 single probe. The Mi805 offers you a combination of pH, conductivity, total dissolved solids and temperature measurements with an EC range of 0.00 to 20.00 mS/cm and a TDS range of 0.00 to 10.00 ppt. You can select from a range of calibration buffers and also the temperature scale (°C or °F) can be selected. The multi-parameter probe MA851D/1 includes pH/EC/TDS and temperature, all in one rugged handle. Other features include different TDS factors from 0.45 to 1.00, and a range of temperature coefficients (ß) from 0.0 to 2.4% for greater consistency and reproducibility. The stability indicator prompts the user when the reading stabilizes. The auto-hold function automatically freezes reading for later viewing. Large and easy-to-read display provides simultaneous readings of pH and temperature or EC/TDS and temperature.