This product is perfect for moving large volumes of hot and cold air at a constant temperature. Applications include: portable blowers and heaters, temporary ship construction ventilation, welding fume removal, and utility manhole ventilation portable heaters. This ducting (type UB1) is factory pre-insulated, flexible, and lightweight. It will not mildew or rot and features an exterior scuff strip to resist abrasion. Retractability is approximately five to one.