GQ-300 Modified Atmosphere Refrigerator is a kind of Laboratory Refrigerator with microelectronics technology, is for making preservation experiment on fruits, vegetables, flowers and plants in modified atmosphere conditions, and keeps them fresh by controlling concentration of O2, N2, CO2, and C2H4 and the temperature and humidity in the boxes. It is widely used in industries of microorganisms, environmental, food, research institute and so on.