Print this with PETG, heat it up with a heat gun to (gently) soften it, and push it around the small nut that connects the PTFE tube to the top of your MK3 or MK4 printer (other printers may work, but I haven't checked). Includes holes so you can hang it up on a hook in case you have multiple filament sources that you want to switch between.

Includes STL file for printing, or 3mf if you want to open it right in PrusaSlicer. Also includes original f3d file if you want to tweak the design.

Supports: No