This electric surface mounted thermostat has a Single-Pole, Double-Throw (SPDT)
contact mechanism and is designed especially for mounting on pipes.
As a high event temperature control, the contacts that open on a rise in temperature are
used. As a low event temperature control for use on unit heaters, the contacts that open
on a decrease in temperature are used. It can also be used as a convector or fan coil
changeover control to automatically select either the heating or cooling function of wall
type SPDT heating and cooling thermostats.