This is a clip-on holder for filament designed for the FlashForge Finder 3D printer.
See https://www.youtube.com/watch?v=LRWEaEVIMKM for more information on how to use it.
Update 29.Aug 2017: A new version is uploaded (rev2). I have used the filament holder for a long time now, and have some good and bad experiences that led to a new revision. I have also added three holes in case someone finds it useful to park the bowden tube there.