The GDX Series High and low temperature circulating device has three systems: Cooling system and Heating system and Circulating system. The heating and cooling systems are used independently and can be switched to use without waiting and change oil. The circulating system is closed system, there is no water vapor absorption at low temperature, no oil mist is generated at high temperature, improve the service life of heat conduction oil. It's widely used in biochemical, laboratory and other industries, and is often used to provide heat source and cold source for Jacketed glass reactor, reaction tank, and other circulating line.