This is a rotating vent. It rotates 360 degrees to direct the air wherever you want it to go. The diameter at the widest point is just over 6 inches, and the pictured "pipe" piece is quite long and designed to fit inside a 5 inch hose, but I've also added a shorter version and a version to fit a 4 inch hose.

I was originally going to make the vent snap-fit in to the flange, but I had limited time to make it so I wanted to make sure it would work first try and I thought I was more likely to make that happen if I used some small screws that I already owned, so that's what I did. The screws are self tapping M1.2x5 and you will need six of them. There are various screw kits on Amazon that contain this size.

All parts should be printed in the orientation they are sitting in already in the STL. All parts should be printed with no supports except for the vent which needs support around the lip. I used auto generated tree supports. Everything was printed at a 0.2 layer height, and I enabled adaptive layers for the parts that had threads so that the layer height would be further reduced on the threaded sections.