The PRO cooling circulation thermostats are ideal for external applications where rapid temperature changes are required. The cooling output of 0.6 and 0.8 kW, combined with a very small filling volume permit these rapid temperature changes. The thermostats have a working temperature range of -45 up to 200 °C. All devices are fitted with a pressure-suction pump. Hybrid cooling of the refrigerating machine permits cooling using ambient air and, supplementary cooling water.