National Chimney M-Flex 6" x 20" Stainless Steel Standard Liner Kit watt354 Wall straps are required every

Wall straps are required every 4’ on the exterior of the building only

Material 304 Stainless Steel Volume 61 fl

Simply add fuel as your fire dies down to sustain your smokeless flame

7 gr/hr emissions

3/16" tempered glass - thicker and sturdier than standard window glass

National Chimney M-Flex 6" x 20" Stainless Steel Standard Liner Kit watt354 Wall straps are required everyM FLEX standard liner kits are used for wood, oil, coal, and gas appliances. Each of our . 006" (CB) and . 005" (CBF) standard kits comes with installation instructions and a lifetime warranty. This lining kit has been installed in venting applications since 1992 and continues to be the most popular "all fuels" kit we offer. We stock 3" 8" inside diameter (ID) as well as 6" 8" outside diameter (OD) in our . 006" (CB). What's Included 1x Installation