Honeywell 5-1-1-Day Electronic Programmable Thermostat. One program for the weekdays; a separate program for Saturday and Sunday - (Up to 4 periods per day). Energy Savings - Program to save up to 33% on annual heating and cooling costs. Easy to Use - Straighforward display and buttons keep operation and programming simple. Backlit Display - Easy to read, even in dimly lit rooms and hallways. Smart Response Technology - Continually adjust the pre-heating/cooling of your home so you are comfortable at your programmed times. Auto change from heating to cooling. Compatible with heating and cooling plus heat pumps Does not work with electric baseboard heat (120-240V). Soft touch keys.