Ceiling Shutter Frame Material Aluminum Number of Panels 1 Maximum Air Velocity 2000 fpm Overall Height 36 in Rough Opening Shape Square Fits Fan Diameter 36 in Free Area 7.3 sq ft Overall Width 36 in Frame Material Thickness 0.1 ga Frame Depth 1 5/8 in Rough Opening Length 34 in Maximum Pressure 1 in wc Rough Opening Width 34 in Blade Material Aluminum Single Acting/Double Acting Single Acting Closure Type Spring Flange Width 1 3/8 in