Spacer of dimensions (16x57x6)mm for the Universal Stand-Alone filament spool holder, by CreativeTools. http://www.thingiverse.com/thing:508896 The proper spool spindle .stl is included. Only one spacer is needed; it replaces the "centering & locking cone" that you don't need if you stick with one filament brand. Spacer is printed with Bumat blue. Spool spindle is printed with Flashforge OEM blue. Color is very close, but Bumat blue is a tad lighter. So far Bumat is working well in my Flashforge dreamer with clear door.