Fire Damper with Sleeve, Sleeved Fire Damper, Square, Mounting Type Dynamic, Vertical, Nominal Duct Width 6 In., Nominal Duct Height 6 In., Damper Depth 3-11/16 In., Material 22 ga. Galvanized Steel, Damper Height 5-3/4 In., Damper Width 5-3/4 In., Recommended Retaining Angle 2TGG4, Fire Rated 1-1/2 hr., Free Area 0.110 sq. ft., Fusible Link 165 Degrees F, For Use With Low Pressure HVAC Systems, Standards UL Standard 555, NFPA 80, 90A and 101, IBC, CSFM, NYC MEA. This item has been restricted from sale in the following state(s): []