Designed for ventilation applications including HVAC, dryer, grow rooms and tents. Four-layer design makes it more durable and resistant to leaks, tears, and cuts. Steel-wire spiral structure is flexible and easy-to-install in hard to reach places. Constructed of aluminum and thermoplastic; tube can be shortened for various applications. Available in 8' or 25' Available Ducting Sizes: 4", 6", 8", 10", & 12" This ducting is designed for various ventilation, circulation, and heating/cooling transfer applications. It features four-layer protection, making it more durable and resistant to leaks than single-layer designs. The internal layer is made of heavy-duty dual aluminum foil that is fire/flame resistant. Its outer layer utilizes dual PVC thermoplastic that protects the aluminum from cuts and tears while stopping leakage. Each duct tube is held together by an internal steel-wire spiral that is flexible and easy to install in hard to reach places. The ducting can be shortened by cutting the tube to fit various applications. Includes two stainless steel duct clamps. Applications Primarily used with duct fan systems in various air circulation and ventilation projects including hydroponic grow rooms and tents, bathrooms and attics, heating and cooling transportation, and other installations. It is also used to cool AV equipment rooms, closets, racks, and cabinets.