Product review (1 stars): Poor quality and poor design
Mine was not an easy installation.  The dryer vent and wall cut are 16 inches apart. I had a few problems. 1.  The baffle gets in the way and had to be removed.  2. The end for the wall is not crimped enough to fit inside a 4 inch wall pipe.  Sheet metal sheers were required to make it fit and didn't make a clean fit.  3. In the process of jockeying it into place the end crimp broke.  I had to use metal tape to put it all back together.

I would not recommend this product.  I would recommend buying the longer one where it stretches in the middle.  Then use sheet metal sheers to trim it to a smaller size.  Also, this one is really flimsy.  Look for one with a little thicker metal.