It is a duct consisting of a perforated internal pipe made of laminated aluminium with a polyester sheet, all reinforced with spirally wound steel wire.
The thermal insulation is made of glass wool coated with an aluminium foil laminated with a polyester sheet.
Between the inner pipe and the insulation there is a polyester sheet as a moisture barrier.
Thanks to its exceptional flexibility, it is easy to install on circular and oval collars.