How do I fit the 4’’ round pipe into the 3 ½ deep boxes, the hole is oval?

When dealing with a 2×4 wall you must use one of our dryer boxes that is 3 ½ deep. The issue installers run into is how to get that round vent pipe into the oval knockout hole. The best way to get the vent pipe into the dryer vent box is to use metal snips to cut a small cut at the end of the vent pipe to give it some more bend so you can create an oval vent pipe.