Steel construction Controls air volume evenly for 6-in round ceiling diffuser Removable knob operator for adjusting from closed to fully open Use small screw holes on the duct ring for attaching the damper to diffuser Larger screw holes on the duct ring can be used to attach damper to ductwork(optional) Durable brown finish Mounting screws included Color/Finish Family: Brown Series Name: Round Sub Type: Butterfly damper Type: Butterfly damper Diameter (Inches): 6 Height: 1.81 Length (Inches): 7.5 Weight (lbs.): 0.67 Width: 7.5 Drive Cleats Included: Yes Gauge: 28 Insulated: No Material: Galvanized steel S Cleats Included: No Warranty: Limited lifetime CA Residents: Prop 65 Warning(s): No Safety Listing: Not safety listed UNSPSC: 30141500