... used in these working environment such as tunnel, basement, ship building or welding, laboratory ,air-conditioner. flexible duct:/air duct/exhaust duct,ventilating duct,flex ... from -15°Cupto +80°C.Application :Widely used in these working environment such as tunnel, basement, ship building ... municipal conduct engineering,fire-fighting to ventilate or exhaust waste air,dust to supply fresh air.keep more ...