6 In.dia Norm Opn Rnd Stel Zone Cntrl Dampr, For Nominal Duct Diameter 6 in, Damper Application Motorized, Number of Panels Not Applicable, Overall Height 8 1/8 in, Overall Length 6 1/4 in, Rough Opening Shape Round, For Duct Shape Round, Overall Width 6 in, Frame Material Thickness Not Applicable, Blade Material Galvanized Steel, Maximum Air Pressure Not Applicable, Overall Diameter 6 in, Rough Opening Length 6 in, Rough Opening Width 6 in, Damper Type Dynamic