Barometric Damper used on CB 5000 Clean Burn waste oil furnaces that take 10 inch stack. This barometric damper is 9 inches but it comes with a 10" adapter so that it could be used with either 9 or 10" inner diameter pipe (adapter included). This damper is suitable for any brand of waste oil furnace that uses 9 or 10" pipe. This Damper and adapter can be slipped conveniently into a Tee section (Tee not included). Proper draft is an important part of making sure your furnace is operating properly!