Based on the blade used by Duncan Idaho in the desert tunnel. Intended to be assembled with two ¼" (6mm) dowels.
Overall length is approximately 30.5" (776.4mm).
There are two versions of the STL. One has been broken into parts with a max height of 200mm to fit comfortably on a Prusa MK3. The other file has the blade as a single piece so you can either split it as required by your hardware or print all at once (nice!).
The author hasn't provided the model origin yet.