Models 0570V, 0580V and 0590V Thinline Static Curtain Fire Dampers are UL approved for use where building codes require the protection of HVAC ductwork penetrations in vertical fire separations (walls or partitions) that have a fire resistance rating of 4 hours or less, classified for use in static "fans off" systems where the HVAC system is automatically shut down in the event of a fire alarm. These thinline dampers are only 2" (51) deep, making them ideal for installation in narrow fire rated partitions, transfer duct openings, behind grilles or any other application where room is limited. They feature corrosion resistant steel frame and blades for lasting performance and a choice of transition styles and factory installed sleeves to suit duct size, making installation fast and simple.