Round Motorized Damper For Nominal Duct Diameter 8 in Damper Application Motorized Number of Panels Not Applicable Overall Height 3 1/8 in Overall Length 3 1/2 in Rough Opening Shape Round For Duct Shape Round Overall Width 2 5/8 in Frame Material Thickness Not Applicable Blade Material Galvanized Steel Maximum Air Pressure Not Applicable Overall Diameter 8 in Rough Opening Length 8 in Rough Opening Width 8 in Damper Type Dynamic Maximum Air Velocity Not Applicable