... and airtight 3.compressible durable and lightweigh aluminum ducting flexible hose 1.Aluminum fexible duct2.fireproof and airtight3.compressible durable ... and logistic..No special tools required for cutting or fixing.Flexible, compressible & fully "fully retardant". It is robust, ... exhaust system,HVAC , rang hood ,clothes dryer vent ,inline fan air vent ,roof ventilation , ventilator use ,And so on. ...