Broan® Pressure Relief Damper, Series: BD Series, 4 in Duct, 30 ga, Steel, Galvanized

• Combines wall cap and damper into one unit
• Reversible damper can be used for intake or exhaust
• Damper has positive seal works in horizontal or vertical position
• Movable collar aids in sealing cutout
• Built-in bird screen
• Extra long collar for easy connection of rigid or flexible ducting
• Wide nailing/sealing flange
• Can provide code required fresh air ventilation when ducted to furnace cold air return