This Everbilt 5-inch by 25-foot flexible air duct features high-efficiency R8 fiberglass insulation, which contains 50% more insulation than standard R4.2 products to maximize thermal efficiency and lower energy bills. Wrapped in a highly durable, heavy-duty silver jacket that serves as a protective vapor barrier, it is designed for use in standard residential heating, cooling, ventilation, and HVAC systems. The product features an oversized core for fast and easy connection to standard sheet metal fittings and can be cut cleanly to any desired length. This specific item is in used fair condition and may show clear signs of cosmetic wear, handling, or previous deployment, but remains functional for standard low-to-medium pressure air distribution and venting applications