HEAVY DUTY: Damper is spring powered to ensure reliable operation through the toughest of conditions and use FIT: Comes in a variety of sizes and comes approximately 1/4" undersized for easy to drop in installation VERSATILE: Can be used for round flexible or rigid stainless steel liners, factory-built chimneys, or solid pack chimney liners WARNING: This product is for use with wood burning stoves only. Do NOT use on gas log chimneys or appliances The National Chimney Premier Drop-In Damper is a great option for restoration projects for wood burning fireplaces. This heavy duty damper is built to withstand the continuous heat from chimney fires. The drop-in damper is spring powered to ensure reliable operation through the toughest of conditions and use. It can be used for round flexible or rigid stainless steel liners, factory-built chimneys, or solid pack chimney liners. They are ideal for installations where a standard top mounting damper is not suitable. It can still be used with top mounted rain caps, top kits, or other premier tops. The National Chimney Premier Drop-In Damper is made from heavy duty 304 stainless steel and comes with a lifetime warranty. It comes in a variety of sizes and comes approximately 1/4″ undersized for easy to drop in installation. It is also recessed approximately 6 inches below the flue’s termination point and includes a 50′ cable. This product is for use with wood burning stoves only. Do NOT use on gas log chimneys or appliances.