PC4-M10 Filament Filter

A filament filter that snaps on to a PTFE tube, using a PC4-M10 coupler.

Put a small piece of foam inside of it and ram a pointy piece of filament through the entire filter several times.
This is to form a hole and remove any chunks of foam that you ripped out with the filament.

For easier insertion you might want to chamfer the end of the PTFE tube.