... hose 1.Aluminum fexible duct 2.fireproof and airtight 3.compressible durable and lightweigh combine flexible duct 1.Aluminum ... tested on fire resistanceAluminum Flexible DuctConstructed of a heavy duty 3-ply, aluminum foil laminate, encapsulating a high density, ... system, hydroponics exhaust system,HVAC , rang hood ,clothes dryer vent ,inline fan air vent ,roof ventilation , ventilator use ,And so on. ...