This is a Heat Shrink dispenser.
You can stack them using magnets.
If you pull too much out you can retract it.
I used a drill to wind them.
Every corner got M2 Heat-Set Inserts and M2 screws.
Printer:
Craftbot Plus
Rafts:
No
Supports:
No
Resolution:
200
Infill:
30
Filament: OwlSat PLA Black