4" x 8' of clothes dryer duct and also includes D2D (duct to dryer) connector. Connects clothes dryer exhaust port to exhaust duct. Clamp-free design (no tools required). Main duct connection elbow with friction fits connection to dryer. Plastic made of UL94 rated, flame-resistance for a safe connection to clothes dryer exhaust port. Enables dryer to be placed close to a wall and preventing dryer from crushing the duct. D2D easily removed from exhaust port to allow for regular cleaning.