7.9 inH 16 inL 15.7 inW GStl Fire/Smke Dampr For Nominal Duct Diameter 8 in Damper Application Fire and Smoke Number of Panels 1 Overall Height 7 7/8 in Overall Length 16 in Rough Opening Shape Square For Duct Shape Square Overall Width 15 5/8 in Frame Material Thickness 20 ga Blade Material Galvanized Steel Maximum Air Pressure 4 in wg Overall Diameter 7 7/8 in Rough Opening Width 8 in Damper Type Dynamic Maximum Air Velocity 3000 fpm Nameplate Voltage 24V DC