Honeywell RET97D0D1003/U 7-Day Programmable Thermostat 7-day menu-driven programming with 4 periods per day Universal compatibility - works with virtually all system types Large backlit display shows room temperature, set temperature and current time all at once Maximum comfort - Smart Response Technology learns the amount of time a system needs to reach a desired temperature and adjust accordingly Ships in Certified Frustration-Free Packaging Auto change from heat to cool