4" 3 Hour Vertical Mount Fire Door 2665-20 Step Down Ceiling Diffuser Standard Features * 1/2" spaced

Standard Features * 1/2" spaced vision-proof dual angular louvers for strength and maximum free area * Margin edges are 7/8" projection for baseboard installation * Soft White with color matching screws Options * 1133 - 1/3" spaced dual angular louvers * 1175 - added mullion stiffeners for greater strength * Standard Color

T-20 Tamper Proof Screws

Minimum size 4"x4"

For damper free area chart A click here * 2563 - Out-of-Airstream fire door

904 - Double Deflection Adjustable Aluminum Blade Grille For a 24" x 24" Duct Opening (front blades parallel to shortest dimension)

4" 3 Hour Vertical Mount Fire Door 2665-20 Step Down Ceiling Diffuser Standard Features * 1/2" spacedh3. 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"