DuraFlex SS Stainless Steel Chimney Liner - 5.5" x 20-ft. - 55DF316-20: A 6" inner diameter vent pipe is required for this unit. If you have a straight chimney, this chimney liner is the most cost-effective and durable solution. This stainless steel 20-foot chimney liner is tough and long-lasting. It has a 5.5" diameter and a .006" metal thickness. When compared to other light weight chimney liners, this product is remarkably sturdy. To fulfill the UL 1777 standard for brick chimneys and wood burning appliances, the chimney liner is designed to be used with the DuraVent DuraFlex Zero Clearance Insulation Sleeve. For your peace of mind, this liner comes with a limited lifetime warranty.

DuraFlex 20 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