DuraFlex SS Stainless Steel Chimney Liner - 5" x 20-ft. - 5DF316-20: A 5" inner diameter vent pipe is required for this unit. This item includes 20 feet of DuraFlex SS in a 5" diameter chimney liner. It is stronger than many other light liners due to its thin thickness of 0.006". For straight chimneys, it is the most cost-effective liner. The DuraFlex SS system allows for effective heating appliance venting, while also protecting the brick chimney from the harmful chemicals found in flue products. To comply with the UL 1777 standard for brick chimneys and wood burning appliances, it should be utilized with the DuraFlex Zero Clearance Insulation Sleeve.

DuraFlex 20 Stainless Steel Chimney Liner 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