PRO1® Programmable Thermostat, 24 VAC, 50/60 Hz Frequency, Programmability: 7 day or 5/1/1 Programmable, Changeover: Auto, Battery, Hardwired Power Source, 3 Heat/2 Cool Stages, 8 sq-in LCD Display, 0.2 to 2 deg F Differential, 32 to 105 deg F Ambient, +/-1 deg F Accuracy, Wall, Junction Box Mounting, Terminal Designation: RH, RC, C, Y, Y2, W/E, W2 G, O, B, Gray, Dimensions: 4.4 in H x 4.7 in W x 1.1 in D