Filament dust filter and roller guide for Ender 2 Pro / Ender 3

It just snaps together. You just need to add some sponge to the top and bottom.

It's a bit fragile with regular PLA, but if you are careful, you'll be fine. I used Fiberlogy's Impact PLA and it's super solid. 

Top cover needs supports when printing. When installing the roller, use the groove on the side to lessen the stress on the bottom's “fork”. It allows you to insert the roller one hole at a time.