Material: POLYSTYRENE Assembled Product Length: 3.5" Assembled Product Height: 19" Assembled Product Width: 12" Diameter: 4" . Clothes dryer can now be pushed up against the wall, saving space Duct will be prevented from crushing Lint build up is minimized due to limited bends and kinks Features a built in draft blocker to reduce cold air back draft Includes oval to round duct adapter