Honeywell TC500A is a smart thermostat that is used in commercial buildings to make the environment more comfortable and help save energy. It consists of a display module and a universal wall plate. The modular design can help to extend a serial product to meet different requirements and easy to change or upgrade. With 4 levels of access and control, TC500A can meet most usage scenarios, including public area, office, and private area. TC500A is the most compact commercial thermostat in the world. Protruding glass and 2-color and groove housing design make it looks even slimmer and sleeker.