The .gcode is sliced with already hexagonial bottom (on the photo is the older version of hte holder, the newer is with better bottom), on the other hand the .stl is upside down, relative to .gcode. The screw hole is 4mm wide. For now the holder isn't mounted, but I will update it as soon as I am done with building the ENCLOSURE.
The author hasn't provided the model origin yet.