TPI's Heating / Cooling Low Voltage Programmable Thermostat includes advanced temperature control ensuring total comfort by minimizing temperature variations and selectable cycles mean thermostat can be optimized to heating / cooling system. An Early Start function ensures programmed temperature is reached by programmed time and an Automatic Daylight Savings feature automatically sets clock ahead or back. Remote input enables change of temperature modes from phone ( Aube telephone controller required ) or alarm / automation system ( 12 VDC transformer required ). Unit is complete with backlit display for easy reading and has an on-screen filter change indicator. Thermostat is Energy Star Compliant and includes 3 Interchangeable Cover Plates - Taupe, Charcoal, Titanium.