Product Sizing Guide Sit in front of your fireplace. Stick your head in the fire box and look up. What do you see? Circle Square/Rectangle Chains/Cables Empty Hole Something Else There is no Handle There is a handle Butterfly damper with handle Round trap door damper Square trap door damper Butterfly Damper High Butterfly Damper Low Handle in Center Handle on Side No Handle Present Vestal damper high flue tile Vestal damper low flue tile Bevel Gear Damper Swing handle damper with supports Swing handle damper Multi-hinge damper Rumford damper Rectangle butterfly damper Slip Knuckle Damper with Side Handle Welded Side Handle Damper Side-Handle Vestal Damper Vestal Damper with Worm Gear Twist-Knob Damper with No Handle or Opening Hardware Chimney Top Damp with Cable Down the Flue Long Rectangle Center-Pivot Damper with Chains Square Center-Pivot Damper With Chains Hanging Down Wide-Open Smoke Chamber and Flue, No Hardware Metal Damper Frame, But No Damper Door Wood Burner with Doors Coal Fireplaces, Inserts, Heatelators, and Other Weird Applications Chimney Top Flue Tile Opening Start Over