Backdraft Damper, Wall Mount, Damper Size 8 x 8 In, Overall Size 10 3/4 x 10 3/4 In, Flange Width 1 3/8 In, Max Velocity 2000 FPM, Construction Material 16-gauge Extruded Aluminum Frame, Aluminum Blades, Galvanized Steel Tie Rods and Stainless Steel Hardware, Includes Felted Edges For Quiet Operation RestrictionsWARNING: Not for use with kitchen exhaust applications. Wall-Mount16-ga. mill-finish extruded aluminum frame, 1-1/2" deep with 1-3/8" flange. Mill-finish aluminum louvers have galvanized steel reinforcement strip. Spring close for positive seal.Backdraft DampersFor belt-drive centrifugal roof and wall ventilators. Max. velocity: 2000 fpm for models up to 19" and no-flange, 2250 fpm for 23" and larger.