Backdraft Damper with Spring-Loaded Folding Blades Ducting in Range Hoods, Fans

4" Backdraft Damper, One-Way Ducting Insert with Spring-Loaded Aluminum Flaps, A

4 In. Steel Backdraft Damper

6 Inch Draft Blocker Backdraft Damper Duct Vent Preventer for Airflow Control

Tjernlund BD-4 Spring Return Backdraft Damper for 4" Ducts

4 Inch Backdraft Damper 2 Pack Spring-Loaded One-Way Airflow Duct Damper

3” Backdraft Damper

Therwen 6-Inch Backdraft Damper with Sleeve for HVAC Duct