3in Duct Square Flange

This goes along with my Elegoo Centauri Cabon 3" Vent: https://www.thingiverse.com/thing:7283421

I've seen other Elegoo Centauri Carbon exhaust ducts, but they all seem to be 4in. I wanted 3in as the amount of flow out of the exhaust fan it minimal and 4in seemed like overkill. So this is the piece that I attached to the window insert.

This was modeled in Onshape, so the model is available to anyone to copy and tweak as they see fit:
https://cad.onshape.com/documents/5c5e3015a7d2b0f888b41120/w/6ac0d3bfb129ab9372b9215a/e/94e572fd09a5ec72189c5263?renderMode=0&uiState=697a1a9324f0e0b53b2b4d58