4" Inch 90 Degree Duct Connector -Elbow- Dryer Vent Pipe Elbow Metal Tube for HVAC - Amazon.com
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
Charlotte Pipe 3/4-in 90-Degree Schedule 40 PVC Elbow (10-Pack) in the PVC Pipe & Fittings department at Lowes.com
3/4 in. 3-Way Elbow PVC Fitting (Box of 100) — FORMUFIT Direct
4" x 12" Legs 90 Degree Exhaust Elbow ID-OD Aluminized L400F