A thermal controller is a precision thermostat which is designed to maintain the temperature of a device or enclosure within a pre-determined range. The contact configuration, the differential/hysteresis and the tolerances of both the set and reset temperatures can be specified within published parameters. Contacts are available to open or close on temperature rise or fall thus eliminating the need to depend on the reset temperature of a lesser device to perform your primary task. This is ideal for applications where a contact must operate on temperature fall in order to prevent freezing or similar outcome.