
Durable PVC Coated Fabric Flexible Ventilation Duct for Underground Tunnel Usage. Customizable Dimensions: Diameter 300-3200mm and Length 3-20m available upon request. Four Color Options: Available in Yellow, Black, Orange-Red, and Green. High Tensile Strength: Customized material strength ensures durability in warp and weft directions. Eco-Friendly Material: Made from PVC composite polyester fiber, odorless and safe. Flame Retardant: Meets European and American safety standards with fire-retardant properties. Low Airflow Resistance: Double-sided PVC coating reduces friction and minimizes air leakage. Versatile Applications: Suitable for marine, mining, firefighting, and industrial ventilation. Multiple Connection Methods: Supports Zipper, steel ring, and Velcro connections.