... airtight 3.compressible durable and lightweigh aluminum ducting flexible hose 1.Aluminum fexible duct2.fireproof and airtight3.compressible ... aluminum foil laminate, encapsulating a high density, corrosion resistant wire helix, forming an air tight, easy to use, quality air connector ... The products have been tested on fire resistancePVC & Aluminum combine ductIt'sa flexible ducting with a reinforced ...