This is a non-functional part. It does not reduce sound nor does it extend the barrel. It just looks cool. It replaces the factory flash hider and covers the part of the barrel that sticks out past the handguard.
I recommend printing with the muzzle-end (the slightly rounded end with a smaller hole) up and with a brim to help with bed adhesion. It's not threaded but the barrel threads will bite into the plastic. I have not tested it with live fire at the time of upload.
The author marked this model as their own original creation.