8" X 13" Yuco Lock Tight Cable Damper Chimney Top Damper Replacement + Chimney Cap. Your Chimney / Fireplace Damper Is Rusted and is no longer closing properly. Now You have all your A/C's Cold air jetting up your fireplace like there is no tomorrow. Your Electric is Bill is Way up there and now you know why! Replace Your Old out dated damper with a Yuco Lock Tight Energy Savings Damper Cap. Damper Cap Easy Installation Air Tight Gasket Seal YuCo Lock Tight Damper Functionality Energy Saving