While working on some other segments for the known diamaters I'm also working on a new standard that is especially made for small areas (e.g. cupboards, etc.). 

The example below is a filter system that I want to install in my 3D printer chamber. The Idea is that air from the top is sucked in, through the new HEPA filter segment and then release in the chamber again. This way I try to collect and filter the exhaust air of my 3D printer while staying as compact as possible.

What do you think about it? :)