Thermostat FT18R

The electromechanical thermostats in the FT series are
designed around a gas-filled capillary tube and sensor housing that
transmits temperature changes to an alternating relay. The relay
can break up to 15 A at 230 V AC.

The FT series consists of anti-freeze thermostats that protect
air heaters in ventilation or air conditioning systems and
heat exchangers in cooling systems. They can also be used for
to control electric heating systems and to activate optical or
acoustic alarm signals.