Lambro 4-in Dia Aluminum Dryer Vent Extender in the Dryer Vent Extenders department at Lowes.com
Amazon.com: 10" Inch Metal Vent Duct Connector - Vent Extension - Galvanized Metal Pipe Connection - 10 Inch Dryer Vent Coupler - Metal Dryer Pipe Coupling - Rigid 10" Inch Metal Hose