This is a modified version of cmetzels filament guide to accept a felt dremel polishing wheel (#414) in the back to clean the filament instead of a sponge. Its length also helps keep octave filament from jumping off the spool and it is a better fit if you are using the official solidoodle case. The inside piece is unchanged, so if you already printed cmetzel's original you only need to print the outside part.Print both parts Feed your filament thru: -A felt dremel polishing wheel -Then thru the filament guide -Thru back of SD case -Thru threaded inside guide -Screw guide into place -Then insert filament into extruder