You can trust and enjoy the service of your gas furnace more when it is properly vented. Empire's flue outlet vent tube makes this possible even with walls between 13-19 inches in thickness. It becomes an essential venting if you have super thick walls or other space challenges or restrictions. This extension tube is specifically made for the Empire DV210SG and the DV215SG gas furnace installations. Safe and economical venting is a win-win for the conscientious homeowner.