Model:FD-AOW Curtain Fire Damper - 1-1/2 Hour - Static - Sleeved - Out of Wall
APPLICATION UL classified for installation the grille and damper assembly does not allow for mounting in the plane of the fire barrier with a fire rating of less than 3 hours. This damper may be installed vertically or horizontally in static HVAC systems that shuts down in the event of fire.