I created an extension to the existing HEPA filter model that fits the Atomstack P1 laser engraver. I use the 50 mm tube that comes with the machine to connect it to the filter block.

You need 2 (or 4) M3x25 mm screws to fix it to the front cover.

Printed without support, though the upper horizontal part does not come out so nicely on the inside and sags a bit.

I attached the openScad file as well. Feel free to modify and fit to your needs. You will need the BOSL2 lib (https://github.com/BelfrySCAD/BOSL2).