This is a visually reconstructed copy of Prusa Research's P-Drill*. The drill was a part of the i3 MK2 to MK2s upgrade and was used to enlarge the bed mounting holes for U-bolts.

The part was not included in the latest MK2.5S upgrade kit (and I couldn't find it online).

Some similarities/differences between the K-Drill and P-Drill:

• This takes a 1/8" drill bit (3.175 mm)

• Two 12mm socket cap M3 screws are used to secure the bit

• Two M3 hex nuts are inserted in the slots to capture the screws (but square nuts can also be used)

• This is the K-Drill to distinguish it from the P-Drill

* https://manual.prusa3d.com/Guide/1.+Y-carriage+drilling/323