Thermaflex 12"x25' R8 Insulated Flexible Duct

Thermaflex flexible ducting is UL 181 Listed Class 1 air duct. Strong polyester film laminated and encapsulating a heavy steel wire helix forms the inner core. The outer silver film provides a reflective surface on the inner core. An oversized, loose, steel wire helix supports a thick blanket of fiberglass insulation creating an air gap between the reflective inner core and fiberglass insulation. The outer vapor barrier is a jacket of durable black polyethylene. The smooth airtight inner core of polyeste...