This ventilation flexible air duct hose machine is special for production the fire resistant flexible ducts with U -lock steel strip reinforce. The flexible fabric air duct hose is telescopic resistant steel skeleton with negative pressure ventilation tube, Nylon telescopic ventilation hose size and length according to customer request processing. The Industrial flexible canvas air duct is produced by the coated fabric, and can be coated by Silicone, Fiberglass, Polyurethane, Neoprene and PVC material, etc. So that the fire resistant air ducts can be chosen by clients, suitable for different places. If you are interesting in this duct machine, pls feel free to contact with us! Mail: Jv@jack-aiva.com Whatsapp: +86 13915206868