Honeywell 7 Day Programmable Thermostat Helps you save up to 33% on your energy bill, Program each day differently, up to 4 periods/day Precision temperature control, +/- 1F Accuracy, Easy to read backlit display, easy programming Early start function ensures temp reached on time, Compatible with heating/cooling/heat pump systems F or C temperature display, 12 or 24 hour clock, Includes mounting hardware and quick install guide Requires 2 AAA batteries (not included), Thermostat: 5.5" L x 3.75" W x 1.25" H