Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:3908811.

A PTFE Holder (used with pneumatic fitting PC4) with embedded dust filter. Can be fixed with M5x10 DIN7991 bolt to v slot type extrusion. Cover the bolt with provided plug. Put some foam inside and you're good to go!

UPD To screw in the fitting, please use some solvent, or cut a thread beforehand, so the fitting won't break its groove