Product review (4 stars): Installed quite easily
At first appearance this thing looks cheap and flimsy, and it's light as a feather too, so I had my doubts removing it from the box that it would do the job.  It comes completely compressed, so the first thing I needed to do was to stretch it out and shape it into an S (exactly like the picture shows for my install).  Best advice here is to go very slowly, don't just yank it, and try to get it to stretch open uniformly rather than just in the middle or at one end.  The bending part is the trickiest, and here again best to work it very slowly.  I found it helped putting one hand inside the tube for support while bending to keep the material from kinking too much.  If you get a kink, you can gently push it out a bit, just don't be too aggressive or you could easily put a crack in the tube.  Making the end connections is easy, I put 3 slits on the collars at each end so they'd slip over the mating vents, and used worm gear clamps to hold it in place.  I also used a very tiny bit of aluminum tape just to seal the small gap where I had cut the 3 slits a bit too long on one side (some people like to put tape all the way around the connection however that's not a good idea as it makes it harder to do your annual or biannual lint inspections).  Finally cranked up the dryer to make sure there were no leaks, and there weren't, so the flimsy looking product ended up making a very solid install, and at a great price!