From inside (document excerpt):
Honeywell T8000C Programmable Thermostat. Free Installation Instructions in PDF.
The T8000C Thermostat provides single-stage, programmable temperature control for 24 Vac heating-cooling systems with manual changeover from heat to cool.
Heating cycle rate is selectable at 1, 3, 4, 5, 6, 9, or 12 cph. Cooling cycle rate is fixed at 3 cph. Temperature indication can be set for °F or °C. The T8000C Thermostat is powered through the heating/cooling system controls. Batteries are not required because setpoints are held permanently by non-volatile memory.
Source: honeywell.com