The DuraTech 8 Class A Chimney Pipe Adjustable Roof Flashing for 13 12 - 18 12 Pitch Roof flashing is used to weather proof the penetration of chimney pipe through the roof. Storm Collar required. Select roof flashing based on pitch of roof. for example, a 6 12 pitch has a vertical rise of 6 over a horizontal distance of 12. Made of galvalume. 6-8 available with large base.Fuel Type: Coal, Gas, Oil, Wood Height: 8 Length: 38 Material: Galvanized Steel Pipe Class: Class A Pipe Inside Diameter: 8 Pipe Shape: Round Pitch: 13 12 - 18 12 Style: Functional UL Listed: Yes Weight: 12.5 Width: 22