... ship building or welding, laboratory ,air-conditioner. flexible duct:/air duct/exhaust duct,ventilating duct,flex duct1,Material: PVC flam-resistant static-free fabric ... ect.5,Character: enduring high temparature,acid,alkali,oleic acid, harmful liquid state gas ect.Temperature range:from -15°Cupto ... connect to the portable ventilator to use together. high temperature flexible duct with metal ring