The Honeywell RTH221B is a white, wall-mounted programmable thermostat with a rectangular shape and a 1.76-inch digital display. It is compatible with universal systems and has a temperature sensor technology. It is powered by batteries and has a push-button control style. The thermostat is programmable for seven days and has an auto system switching feature. It is designed for gas, oil, electric, or heat pump systems and has a single cool stage. The Honeywell RTH221B is Energy Star rated and features a digital display.