A B Blade Material: Aluminum , Blade Material Thickness: 26 ga. , Blade Orientation: Parallel Blades , Blade Seal Material: Felt , Blade Type: Flat Blade , Fits Fan Diameter: 8" , For Duct Shape: Square , Frame Depth: 1 5/8" , Frame Finish: Galvanized , Free Area: 0.3 sq. ft. , Max. Air Velocity: 2250 fpm , Max. Ambient Temp.: 180 Deg. F , Max. Pressure: 1" wc , Mounting Location: Wall , Mounting Position: Vertical , Overall Height: 10 3/4" , Overall Length: 4 1/2" , Overall Width: 10 3/4" , Rough Opening Diameter: 8 1/2" , Rough Opening Length: 7 1/2" , Rough Opening Shape: Square , Switch Action: Normally Closed , Tie-Rod Finish: Galvanized , Tie-Rod Material: Steel , Type: Wall Mount, Supply
Damper Backdrafts
Dayton damper backdrafts are suitable for use in ductwork, roof curbs or wall collars when using a fan or power roof ventilator. The blades of these dampers are provided with a felt seal on the leading edge for superior protection from the weather and are spring supported to permit blades to open comfortably. Choose from a range of these damper backdrafts, available in 1.375 and 1.5-inch widths.