DuraPlus is designed to stay cool on the outside, to provide a hot draft on the inside, to boost stove efficiency, and to provide for a fire-safe design that protects both the chimney and the building. This triple-wall chimney features two insulating layers (ceramic blanket, plus air space). The ceramic blanket insulation is held securely in position, eliminating hot spots common with loose-fill type insulations. In the event of a creosote fire, the compressible blanket insulation permits the chimney liner to expand outwardly in a radial direction. DuraPlus Chimney is a triple-wall, all-fuel chimney for use with wood stoves, fireplaces, furnaces, boilers, stoves, ranges, water heaters, or other appliances fueled by wood, oil, coal, or gas. Perfect for Any Wood stove with a 6 Inch Flue. Safe, triple-wall design. All-in-one kit saves time and guesswork 6" chimney pipe sold separately. Supports up to 40 ft. of DuraPlus chimney pipe (not included). Includes a wall thimble, one 9 in. x 6" horizontal chimney pipe, 1 tee with clean-out cap, 1 tee support, 2 wall straps and 1 chimney cap. Twist-lock design. Used for a through-the-wall vertical chimney installation.