Rubber-Cal "Air Ventilator Heavy-Duty" Ventilation Hose (Fully Extended) - 12-Inch by 25-Feet Ultra-durable, heavy-weight flexible air duct Highly compressible flexible air duct that is easy to transport Built-in wear strip offers flex duct external abrasion resistance for heavy-duty applications Retract ability allows for convenient storage and easy transport in a fraction of its fully extended length Thick PVC vinyl-coated polyester flexible hose reinforced with a spring steel wire helix and external wear strip