Air Tight Industrial Flexible Duct is designed for HVAC systems is light weight, strong, fully flexible and compressible yet dimensionally stable. The Flexible Duct is made of double lamination of films permanently bonded to a coated spring tough steel wire helix. The Flexible Duct is provided with thermal efficiency is provided by wrapping the exterior with a blanket of fibreglass wool insulation in various densities and thicknesses for required thermal resistance. Air Tight Industrial Flexible Duct is strong and rigid in construction and requires minimal maintenance.