Hunter 44100B is a programmable thermostat designed for various heating and cooling systems, including gas furnaces, electric air conditioners, and oil-fired boilers. It features a large display that shows the time, day, temperature, program number, and other information. The thermostat can be programmed with up to four daily programs, each with four temperature settings. It also has a permanent hold feature that allows you to set a temporary temperature that overrides the programmed schedule.