Marketing InformationHighly efficient, thermally insulated flexible duct for use in low and medium pressure heating and cooling systems. New and improved bi-directional reinforced metallized vapor barrier will not unravel. Acoustically-rated, self-extinguishing chlorinated polyethylene (CPE) core easily expands over fittings. Core is permanently bonded to a coated spring steel wire helix that supports ample blanket of fiberglass insulation, providing a double air seal.