KVM Tools 4C556 12 in Backdraft Damper Wall Shutter, 12 1 2 in x 12 1 2 in G5050261 Standards FDA Compliant Standards FDA Compliant Displacement per Stroke 2nd Stage 0 Fits Fan Diameter 12 in 8 in Damper Application Backdraft Fusible Link Temperature Not Applicable Switch Action Normally Closed Frame Material Aluminum For Fuel Type Not Applicable Blade Type Flat Blade Rough Opening Shape Square Closure Type Gravity Frame Less Flange 12 Maximum Pressure 1 in wc Opening Type Gravity For Duct Shape Not Applicable Damper Type Static Damper Finish Mill Finish Connection Type Not Applicable Maximum Air Velocity 2500 fpm Package Quantity 1