Ø127mm x 10M insulated, corrosion-resistant aluminium flexible ducting consists of an aluminium laminate inner duct and is thermally insulated by a glass wool layer in an aluminium laminated outer jacket. The thermal insulation is suitable for preventing condensation and heat loss. Ideal for ducting systems located outside of the thermal envelope of a building. NOTE: As per UK Building Regulations Approved Document F Vol. 1: Dwellings; flexible ducting, where installed, must only be used for final connections and be a maximum of 1.5M in length., Weight: 1.543235834 pounds, Manufacturer: Airflow