... noise, strong wind, strong effects of ventilation2.Shutter introduce the principles of air downstream and synthetic PVC blinds, antioxidant, ... it's light weight, high strength and good tensile4.Using the imported bearing, high strength, low noise and durable5.High ... of fan, small wind resistance, the structure is more reasonable6.Wind capacity is 46500m3/h New type, Butterfly cone fan for greenhouse/ ...