PRECISE TEMPERATURE CONTROL: Precise temperature control of +/- 0.5 degree Celsius. DIGITAL DISPLAY: Easy-to-read digital display. SIMPLE TO USE: Simple, soft-touch buttons allow you to select the temperature quickly and easily. EASY-ACCESS: Easy-access battery compartment and change battery reminder. SET POINT RETAINED: Set point is retained in memory in the event of a power outage. COMPATIBLE WITH: Heating, cooling and heat pumps without auxiliary heat options. NOT Compatible with: Does NOT work with electric baseboard heat (120-240 V), heat pumps with backup, or multi-stage heating/cooling.