Product review (5 stars): Needs an adapter
Here is the deal. According to the manufacturer you need to buy a extender to go threw the wall of the house. What I did was used a cheap tin one from the hardware store and used clear silicone to seal it to the elbow and used some self tappers to go threw the plastic elbow to the cheap tin.

The product itself is a very intelligent design that keeps the cold air out very well, much better then the cheapo louvers from Home depot.
The negatives are it is kinda large on the side of your home. But the good far outweighs the bad.