Product review (5 stars): If you need to move air (or other things) 50ft away and for cheap, it does it great
I used this as a makeshift A/C duct, to transfer the in-wall AC's output to another room(temporary setup)

Of course i had to make an adapter bracket to take the rectangular AC output to this 4" circle, but it did work pretty well.

The main thing to keep in mind is that this is not insulated(but probably better than foil duct), so if used as i used it, you'll lose some energy along the way.

It's under 20 bucks, which is a pretty great bargain for such a length/diameter. the material feels satisfyingly rugged, but i sure wouldn't step on it or drop anything sharp on it.