SS Motrzd Vent Dampr 6.1 In.L 8.9 In.H 6.1 In.W For Nominal Duct Diameter 4 in Damper Application Vent Number of Panels Not Applicable Overall Height 8 7/8 in Overall Length 6 1/8 in Rough Opening Shape Not Applicable For Duct Shape Not Applicable Overall Width 6 1/8 in Frame Material Thickness 0.024 in Blade Material Stainless Steel Maximum Air Pressure Not Applicable Overall Diameter 4 in Rough Opening Length Not Applicable Rough Opening Width Not Applicable Damper Type Dynamic