Product review (1 stars): Really thin duct - JUNK
USED FOR: Connection from clothes dryer to wall exit.
PROS: Both the "male" and "female" ends are ridged and work well for connecting incoming/outgoing pipe.
CONS: Although the accordion like pipe appears strong when fully retracted at 2 feet long; when you expand it you realize the
pipe is just slightly thicker than using your aluminum baking foil (well not quite).

If you intend to expand the collapsed length of 2 feet at all, the pipe will buckle like a politician who's up for reelection.
I also had a generic 10 foot piece of 4 inch expanding aluminum duct that I had purchased previously for this project,
and it was at least two to three times stronger/thicker than this POS.