Imperial insulated flexible duct, 6 inches in diameter, 25 feet in length (7.6 meters), R-value, energy efficient R-8.0 fiberglass insulation, silver reinforced polyester reflective jacket, durable core constructed with non-corrosive coated wire, used for heating, ventilation and air conditioning, certified 181 class 1 air duct, brand new has never been used, no shipping, local pickup only.