... ,fire-retardant PVC material 2,competitive price,fine quality 3,Oil, Acid, Alkai & high temperature Resistant flexible duct:/air duct/exhaust ... duct,ventilating duct,flex duct, ventilation duct 1,Material: PVC flam-resistant static-free ... fabric with steel wire reinforced.2.PVC Thickness:0.3mm-0.45mm.3,Diameter:4" to 60 ...