15.8 In. H 11.8 In. W 3.7 In. L GStl Grvty Fire Dmpr, Damper Application Fire, Frame Material Galvanized Steel, Number of Panels 1, Maximum Air Velocity None, Overall Height 11 3/4 in, Rough Opening Diameter Not Applicable, Rough Opening Shape Rectangular, Fits Fan Diameter Not Applicable, For Duct Shape Rectangular, Free Area 0.9 sq ft, Overall Width 15 3/4 in, Frame Material Thickness 22 ga, Overall Length 3 3/4 in, Connection Type Not Applicable, Frame Depth 3 3/4 in. This item has been restricted from sale in the following state (s): []