The DTH35 Digital Psychrometer w/Enthalpy is used to help technicians measure temperature, relative humidity, wet bulb temperature, dew point, and enthalpy. The design makes in-duct measurement possible with the 4-inch-long probe, while the magnetic mount allows for hands-free measurement on grilles or other metal surfaces. The unit includes a large backlit display with hold, minimum/maximum functions, and a one-year limited warranty.