AcuRite 01083 Pro Accuracy Indoor Temperature and Humidity Monitor, Original Version Measures indoor temperature and humidity from -4 to 158F (-20 to 70C) and 1-99% RH Professional accuracy: +/- 0.5F, +/- 2% RH with manual calibration option Displays high and low records for past 24 hours and for all-time Measures conditions every 10 seconds Tabletop, wall-mountable, and magnet-mountable design