The White-Rodgers 80 Series+ Blue Digital Thermostat 1F80-0471, Single Stage, 5/1/1 Day, 5/2 Day Programmable or Non-Programmable Thermostat features 24 Volt or Millivolt system, 3-wire zone, Large, 4-square-inch Blue display with easy-to-see characters. Configures as manual heat/cool, auto changeover, heat only or cool only. Exclusive Cool Savings™ feature saves energy during peak A/C demand periods. Hydronic 2 or 3 wire applications. Three anticipation settings. Exclusive battery power monitor with a longer battery life and easy access battery compartment.