ATCO OmniAir 1200 is a UL 181, Class 1 Air Duct and is manufactured with a tri-directional fiberglass scrim reinforced, metallized polyester outer jacket. A triple lamination of metallized polyester, aluminum foil, and polyester, which encapsulates a steel wire helix, forms the air-tight inner core. The multi-layer core is wrapped in a thick blanket of fiberglass insulation. The OmniAir 1200 is designed for low-tomedium operating pressures.