4" Inch 90 Degree Duct Connector -Elbow- Dryer Vent Pipe Elbow Metal Tube for HVAC - Amazon.com
Charlotte Pipe 4-in 90-Degree PVC DWV Elbow in the PVC DWV Pipe & Fittings department at Lowes.com
Amazon.com: Spectre Performance 97990 4" 90° Aluminum Elbow with 7" Leg : Automotive
Amazon.com: NDS 4P02 PVC 90-Degree Elbow, X Hub solvent-weld connections, for Use with 4-Inch Sewer and Drain Pipes, White, 1 Count (Pack of 1) : Everything Else
NDS 4-in PVC Sewer and Drian 90 Degree Elbow in the Sewage Pipe & Fittings department at Lowes.com