The DuraTech 6 x 12 Stainless Steel Class A Double Wall Chimney Pipe Length is designed for appliances that are tested and listed for is used with a 2100° F HT chimney system, such as wood stoves, fireplaces, furnaces, boilers, ranges, water heaters, or other appliances fueled by wood, oil, coal, or gas. Available in stainless steel (SS) or in a galvalume (GA) outer casing and stainless steel inner wall with twist-lock connections.Finish: Galvanized Fuel Type: Coal, Gas, Oil, Wood Length: 12 Material: Galvalume Pipe Class: Class A Pipe Inside Diameter: 6 Pipe Shape: Round Style: Functional UL Listed: Yes Vent Construction: Double Wall Weight: 5.1 Width: 8