Shutter Mounted Industrial Exhaust Fan is designed for use inside the building with vents outside.
快门式工业排风扇，是专为建筑内部排气而设计的。
2
Shutter Mounted Industrial Exhaust Fan models are available with a blade diameter of 12 ", 18 ", 24 "or 30".
快门式工业排风扇根据型号，刀片直径分别为12英寸，18英寸，24英寸或30英寸。
3
The utility model relates to a power switch used for a ventilating fan and a special pulling switch used for the closure and the linkage of shutter blades.