Model series 0500 (steel) and 0500SS (stainless steel), Standard Frame Static Curtain Fire Dampers, for use in static "fans off" systems where the HVAC system shuts down in the event of a fire, are UL approved to provide protection of HVAC ductwork penetrations in walls, partitions or floors that have a fire resistance rating of 4 hours or less. The 0500V/H Series features corrosion resistant steel frame and blades for performance that will last and a choice of transition styles and factory installed sleeves to suit duct size, making installation fast and simple.