This vent extension kit is used for the Category I venting of gas furnaces. The pipe is constructed of aluminized steel and offers greater corrosion resistance than conventional single wall galvanized steel vent pipe. It is not a substitute for Type B vent or Type B vent connectors used out side of the furnace casing.
Warning: this product contains a chemical known to the State of California to cause cancer. P65Warnings.ca.gov