Flexible Duct Connector• All Duro Dyne Fabrics are designed to meet NFPA 90A & 90B.• All Duro Dyne Fabrics are airtight and waterproof.• All seams are secured with Grip-Loc or Guard Loc, a Metal to fabric heavy duty gripping method.• All Duro Dyne Flexible Duct Connector utilize 24 or 28 gauge (.7 mm or .47 mm) galvanized steel meeting ASTM-A-525 G60.• All Duro Dyne Fabrics are designed to meet NFPA 701 (formerly UL 214.)*• Flexible Duct Connector is available with 300 series stainless steel or aluminum.• Duro Dyne Flexible Duct Connector is manufactured in the United States.*Due to the multitude of duct connector configurations offered, please reference our Duro Dyne submittals forms for your specific application needs.