4 Inch Airbrush Filter

I designed and printed this a couple years ago so that I could have extra filtration while using my airbrush spray booth. The booth has its own filter and fan and has a 4 inch hose with a connector that can vent out a window. This is great in concept, except it doesn't do great things for the utility bill. While I know they sell filters similar to this online, I figured I'd make a less expensive model that I could wrap an inexpensive charcoal sheet around that would be inexpensive to replace (in case you didn't pick up on it, inexpensive is the key). I've been using it for a couple years without changing the charcoal sheet and it's still working great.
I use a shopvac on the booth filter and change it out as needed. This setup works well for my needs so I figured I'd share it with you.