The DuraTech 12 x 12 Galvanized Class A Double Wall Chimney Pipe Length DuraTech chimney pipe 10 - 24 diameters are is designed for appliances that are tested and listed for is used with a 1700° F rated chimney system, such as zero-clearance or masonry fireplaces, furnaces, boilers, water heaters, ranges, or other appliances fueled by oil, coal, gas, or wood. Tested to UL 103 and listed under MH 7399. Requires fastening with screws.For class a chimney pipe UL ListedADA Compliant: No Collection: DuraTech Finish: Stainless Steel Fuel Type: Coal, Gas, Oil, Wood Inner Diameter: 12 Length: 12 Material: Galvanized Steel Outer Diameter: 14 Pipe Class: Class A Pipe Shape: Round Style: Functional Weight: 12.2 Width: 14