E-clip for spool holders

I got tired of my spool walking toward the left side of the holder, it probably doesn't matter but it seemed like it put unnecessary tension on the filament. Two of these E-clips right in the middle of the holder, loose enough that the spool can spin freely, will keep it centered. They fit tightly enough to keep from moving around.

I made them in 12mm for my ZMorph VX and also 14mm for the inexpensive Iverntech holder on Amazon. I also uploaded the Fusion 360 file, just change the nominal_diameter parameter for your holder.