Backdraft Exhaust Damper No Flange Horizontal or Vertical Mount Damper Size (In.) 7-3/4 x 7-3/4 Overall Size (In.) 7-3/4 x 7-3/4 Flange Width (In.) - Max Velocity (FPM) 2000 Construction Material G-90 Galvanized Steel Frame and Aluminum Blades Use w/Dayton Ventilators - Includes Pre-punched Conduit Hole Knock-out and Felted Edges For Quiet Operation