Superpro / Supervent chimney by Selkirk are constructed using 304-alloy stainless steel for inner walls, and specially formulated mineral wool insulation to reduce chances of corrosion. Although they have the same connections where they can be used together, there are quality differences between the two products. We carry all 6-inch and 8-inch products in the "Super-Pro" product line, and all 7-inch products in "Supervent" product (note, some non-chimney length components are the same between models).
Double coating process on components like flashing have twice the corrosion resistance of standard galvanized parts. Locking bands are recommended at the straight joints and required at elbows, joints between elbows, and tee connections. Outside diameters of these 6" chimney pipes are 2" larger then the listed ID size of the chimney.