... corrosion resistant 2)high efficient ventilation, 3)high-quality alloy body 4)unique duct 1.Some samplesCharacteristics and ... indoor air to generate the host rotating exhaust,applying to industrial plants,greenhouse,hens for livestock and poultry,and other building. High-quality ... size:width 600mm,height 320mm,thickness 160mm1. High quality plastic,high durability,ageing resistant;2.Close tightly,open ...