4" 3 Hour Vertical Mount Fire Door 2661-48X34 Accessories Allows for 4-way airflow

Allows for 4-way airflow

For damper free area chart B click here * 2565 - Round fire door for vertical mount only

904 - Double Deflection Adjustable Aluminum Blade Grille For a 18" x 4" Duct Opening (front blades parallel to shortest dimension)

Holds up to 1" filter

4" 3 Hour Vertical Mount Fire Door 2661-48X34 Accessories Allows for 4-way airflowh3. Standard Features * 2661 Square or rectangular fire door for vertical mount only. Maximum dimension 60x60. For damper free area chart A click here * 2663 Out of Airstream fire door. Square or rectangular for vertical mount only. Maximum dimension 60w x 52h. For damper free area chart B click here * 2665 Round fire door for vertical mount only. Available 4" thru 52" round. * 3 hour rated * UL and California State Fire Marshall approved * 4 1 4"