This replaces the plastic part on the dust bag of my Dewalt saw. It broke on me years ago, so I didn't have all of the plastic part anymore, but i think i figured it out. This saw is over 10 years old so I guess it has their older style of dust connector. New bags cost about $15 and generally require an adapter as they are made for the newer style. This will cost you about half a dollar of filament. Now I can stop spraying so much dust all over!
The pictures should show pretty well how this put on.
No supports needed. It should load up in the intended print orientation.
I suggest 3 perimeters - mainly so the main tube part prints solid. I used petg for mine, but pretty much any filament should work.
I did have to very lightly sand the inside of mine for it go on smoothly, but it was a great fit.