Felix printers Pro L Quick Start Manual page 15

Then push the filament through the dust cleaner until it comes out the other end then insert it into the head. Ensure the filament is
cut off in a skew manner, so the extruder can easily grip the filament. For abrasive filaments like carbon fiber filled, it's better to take
the dust filters out.
Press the change filament button in the home menu.
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Quick Start Guide FELIX Pro L / XL