flexible ventilation tube

clear air flexible duct for mine, channel, tunnel / flexible air ductChinacoal05 negative pressure flexible duct Usage:1.made of fire-retardant PVC material and helix steel wire PVC2.easily to connect due to flexible3. enduring the high temperature and oleo acid,4. Hose body transverse no juncture, Has no air leakage, Wear-resisting, Corrosion resistance, Animistic, The wind drag small, light-weight,The comprehensive strength etc advantages;5. Main color: yellow,red,orange