I like to position the filament behind my printer in order to remove weight from the top of the printer frame. This is a small filament guide with roller bearings to sit atop the Prusa printer frame to guide filament into the extruder with minimal friction.
Printed with 0.20mm layer heights, 0.45mm extrusion width, 2 perimeters, although any similar settings should work. Bearings are MR105-2RS (4mm axle). Bearings should snap in. Slip joint pliers make fitting easier. I have printer this in PLA and PETG. The clip should be positioned with the thick part to the rear of the printer. Check to verify that travel at maximum Z is not impeded.
The author hasn't provided the model origin yet.