26 In.H-W Aluminum Ceiling Truss Damper Frame Material Aluminum Number of Panels 1 Maximum Air Velocity 1500 fpm Overall Height 32 in Rough Opening Shape Rectangular Fits Fan Diameter 24 in Free Area 4.7 sq ft Overall Width 26 in Frame Material Thickness 0.1 in Frame Depth 1 3/8 in Rough Opening Length 30 in Maximum Pressure 1 in wc Rough Opening Width 24 in Blade Material Aluminum Closure Type Gravity Flange Width 1 5/8 in