Dust filter

Dust filter designed to be compatible with [this threaded filament guide](https://www.thingiverse.com/thing:3254163) as a replacement of the original Prusa i3 MK3 extruder filament guide

Does not require supports. Can fit other cylindrical filament guides as well, if they have inner M6 threads and a maximum of 9mm outer diameter(same as the original).