What is the Honeywell WME Series thermostat and what are its main applications?

The WME Series is a Digital Thermostat designed for 2-pipe/4-pipe Fan Coil Control systems with 3-speed fan and motorized valve control. It supports cool only, heat only, or manual changeover modes, ventilation mode, manual or automatic fan control, and water valve modulating control. The WM423 series is also available in Modbus RTU protocol for building automation system integration. (Page 1)