The Siemens TH 192 S Thermostat is a proportional single output, single setpoint, 2-pipe (high air capacity) sensor controller. It includes a wall mounting plate for installation in a variety of rough-in terminal boxes. A sensitive bimetal responds to temperature change to modulate control air through a flapper nozzle. One setpoint dial (Fahrenheit scale) is provided. Mounting screws are included. This thermostat is a temperature sensing device that controls pneumatic valve and damper actuators in heating and cooling applications such as air conditioners, space heaters, unit ventilators, and air volume controllers. It maintains energy management (maximum economy) and occupant comfort. The cover is designed to expose the setpoint adjustment dial.