Indoor air quality, whole house fans, exhaust and ventilation fans

One Way Air Flow Valve 4" Duct SKU: Tti-CBD4 The Cape Backdraft Damper is an in-line, one way air flow valve. It opens and closes with minimal pressure in either direction. It does not rust or require any maintenance. Fits inside the duct-see here.  The Cape Backdraft Damper works better than other dampers at stopping undesired airflow. It is far superior in that it allows unrestricted airflow in the desired direction without reducing system efficiency. The Cape Backdraft Damper is silent, produces no metal clanging sounds, tested to UL723 standards and can be installed in horizontal or vertical ductwork. Volume discounts available, call 1-800-222-5932 for a quote. Allow one week to ship. UPS ground shipping within Continental U.S. only, all others please call for quote. Click here for additional product information.    Installation video      Technical Data Sheet Price:  $14.00 ea. Shipping:  $15.00 Quantity