DetailsFlex-Vent KM is a thermally insulated, fully lined, UL 181 Class 1 flexible air duct designed for low to medium pressure cooling and heating HVAC systems.Strong polyester film laminated and encapsulating a heavy, corrosion resistant steel wire helix, forms the inner core and supports a thick blanket of fiberglass insulation. The outer vapor barrier is a new bi-directional reinforced metallized vapor barrier which will not unravel. The smooth air tight inner core of polyester is designed for low to medium pressure systems. Box.
California residents: see Proposition 65 Warning