The DTH31 was designed to provide professionals with an easy way to measure temperature and humidity. Packed with useful features, the DTH31 includes a triple display to show three readings simultaneously. Usethe DTH31 when charging air-conditioning systems or for similar HVAC/R applications. Measures temperature in Degrees F and C, Relative Humidity (RH) from 0% to 100% Dewpoint, Wet Bulb, and Temperature and includes Min/Max, Data Hold, Auto Power Off and a Protective Sensor cap