DuraFlex SS Stainless Steel Chimney Liner - 5.5" x 25-ft. - 55DF316-25: A 6" inner diameter vent pipe is required for this unit. A properly fitted fireplace system is incomplete without a chimney liner. DuraFlex's stainless-steel chimney liner has all of the features you need to keep your fireplace operating efficiently and safely. The liner is flexible, allowing for simple installation and a wide range of applications. It's made of a one-of-a-kind alloy that's both light and sturdy, ensuring durability and convenience. The liner can be used in a variety of fireplaces, including those that burn pellets, gas, or oil.

DuraFlex 25 Stainless Steel Chimney Liner 5.5-in. diameter Light-weight .006" metal thickness makes it stronger than other light liners Most economical liner for straight chimneys Manufacturers limited lifetime warranty