Dickinson 3" x 7" Pipe with Barometric Damper (16-010)A chimney pipe with a crimp on one side for connecting, made of 304 stainless steel. The barometric damper is used as the first or second piece of pipe from the top of your heater or stove. The barometric damper helps decrease the draft on longer chimneys allowing the user to operate the unit on lower fuel settings. Recommended on all installs or especially chimneys that are 6ft or taller. (Dickinson chimney accessories are meant to be used only with