1.flexible duct:/air duct/exhaust duct,ventilating duct,flex duct, ventilation duct 2.good quality and fast delivery time Specificationsflexible duct 1,fire-retardant PVC material 2,competitive price,fine quality 3,Oil, Acid, Alkai & high temperature Resistantflexible duct:/air duct/exhaust duct,ventilating duct,flex duct, ventilation duct 1,Material: PVC flam-resistant static-free fabric with ...