PRO1® Thermostat, T600 Series, 18 to 30 VAC, 1 to 1.5 A, 50/60 Hz Frequency, 2 Heat/1 Cool Stages, 2 sq-in Blue Backlight Display, 0.2 to 2 deg F Heating and Cooling Differential, 44 to 90 deg F Settings, 32 to 105 deg F Ambient, 90% Non-Condensing Humidity, (2) AA Alkaline Battery, +/-1 deg F Accuracy, Battery, Hardwired Power Source, Wall, Junction Box, Horizontal Mounting, Dimensions: 4.4 in H x 4.7 in W x 1.1 in D