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.