Corrugated spiral-wound air ducts VA are necessary for laying a ventilation duct with convenient formation of corners and turns. For a simple connection of a hood with a ventilation shaft with a minimum set of fittings. Connection type: triple lock. Material: aluminum foil. Thickness: 70 microns. Operating temperature: -30 to +300 °C. Maximum extended length: 3 m. The air ducts are free to stretch and bend.