Application: animal building, greenhouse, workshop, warehouse equipment configuration: the frame, set air control, fan, motor, transmission, blinds and automatic opening device, protective net Features: 1, low speed, air volume, low power consumption, noise, ventilation effect is obvious; 2, with the shutters automatically open and close without power device, can guarantee the fully open blinds to reduce energy consumption, increase air flow, the fan kept running efficiently. 3, the fan blades rotating shutter opens, stopping when the blinds closed, can effectively prevent the blowing wind and snow in winter and the entry of wild birds.