This Portafilter Funnel can be used for grinding/distributing while also allowing to tamp right through it.
Print with a food safe filament and insert five magnets (3 mm diameter, 2 mm height) via press fit or optionally using a (also food safe) glue.
The included OpenSCAD file allows for easy customisation for different portafilter and magnet dimensions.
The author marked this model as their own original creation.