Vent Systems 4 Inch Backdraft Damper Backdraft Shutter ABS Plastic Inline Duct Connector DraftBackflow Blocker OneWay Airflow Ducting Insert HVAC Exhaust Connector with Valve

PRECISE DIMENSIONS Ducting connector with back draft damper diameter is 390 with insertion depth into vent ducts of 118 inches The backflow damper opens and closes automatically It has a strong spring and can be installed horizontally Easy DIY Designed to provide anti back draught and fit in between Solid Plastic Ducting Flexible Ducting Designed for use in AC dryer vent exhaust extractor or range hoods heating systems fans vents and other residential commercial and industrial HVAC applications Best to use with VENT SYSTEMS hvac parts Duct draft stopper prevent cold air or wind from entering the ventilation pipe In this case the flap is installed in such a way that the flap leaves only open into the outgoing air direction This means that no cold air wind or smell can penetrate the ventilation pipe from the outside The backflow Preventer valve is installed by pushing it into the ventilation pipe as far as it will go The position of the spring should be horizontal when the flap is installed horizontally so that it can be opened and closed optimally This also applies to the vertical installation