The LAUDA LOOP product line includes two thermo-electric circulation thermostats for external temperature control. The temperature control thermostating is by means of a current flow via a semiconductor relay. Both heating and cooling can be achieved simply by reversing the direction of current flow in a small space. The two air-cooled device types, L 100 and L 250, provide cooling capacities of 120 and 250 Watts, as well as a temperature range of 4 to 80 °C. The focus is on applications requiring constant temperature with a low power requirement. Both device types are exceptionally efficient in partial-load operation.