15.8 In.H 7.8 In.W 3.7 In.L GStl Sprng Fire Dmpr Damper Application Fire Frame Material Galvanized Steel Number of Panels 1 Maximum Air Velocity None Overall Height 7 3/4 in Rough Opening Diameter Not Applicable Rough Opening Shape Rectangular Fits Fan Diameter Not Applicable For Duct Shape Rectangular Free Area 0.6 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