This Finishing Band conceals the joints and provides a finished look. When installing stove pipe, the joints appear to be going the wrong direction with a "male-end-up" connection. This is correct for the outer wall. The inner wall is opposite and provides a "male-end-down" connection. Use this to conceal the joint between Double Wall Black Stove Pipe and Class A Chimney Pipe at the cathedral support box or wall pass-thru.