The DuraTech 6 Class A Chimney Pipe Adjustable Roof Flashing for 0 12 - 6 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.Base Dimensions: 27-3 16 x 20 Fuel Type: Coal, Gas, Oil, Wood Height: 8 Inner Diameter: 6 Material: Galvanized Steel Outer Diameter: 8-1 2 Pipe Class: Class A Pipe Shape: Round Pitch: 0 12 - 6 12 Style: Functional UL Listed: Yes Weight: 5