Product review (5 stars): This extension piece was a perfect choice. After two months without a dryer
Since I am replacing siding due to an unusual winter hail storm, I decided to switch out my dryer ventilation system.  My builder used the louvered type that matched the siding.  My top louver was sticking open which let on outside air.  I was afraid I would soon find critters in the house too.  After extensive research, I decided on the heartland vent system.  I believe the extension pipe is for thick walls (mine are not thick), but I wanted a smooth surface to pass through the wall and attach to the interior vent.  This extension piece was a perfect choice.  After two months without a dryer, I am very happy with the system.