The Backdraft Damper attaches to inline ventilation systems to keep exhausted air out for good. When used in conjunction with a fan and carbon Filter, the Backdraft Damper also helps control odors as it prevents any untreated air from escaping the enclosed area. The directional damper installs downstream from the fan: when the fan turns on, the airflow opens the damper, and when the airflow stops, the damper closes. This four-inch Backdraft Damper fits any standard four-inch ventilation ducting.
— Ships from Portland, Oregon USA.
For more information, please visit the manufacturer ECOPLUS's website.