The secures the new MMU3 Prusa Buffer vertically with a large peg using just the center hole in the buffer attachment and side rails to position it. The buffer needs to sit on a surface however.
This bracket should be positioned so the peg goes through the center hole in the buffer. The buffer sits on a surface (or maybe a stand mod). The side guides on this bracket should be covering the horizontal outer beam on the buffer just below, so the grip is more snug.
The buffer is placed over the peg on the bracket and then just sits in place. It can wiggle a little but can't move out of position and can be easily picked up. Nothing is actually screwed into the buffer itself.
Here is the optional MCS larger system that I use it with shown in the pictures. - https://www.printables.com/model/555238-mcs-multi-color-system-for-prusa-mmu
The author remixed this model.
This is not a traditioanl remix as there is not a part I am changing, but this is a new part designed around two parts in the MMU3 buffer. I designed this part specially only to work with the MMU3 buffer, and even more specifically, the triangular hole in the official leg holder part. The sides of my bracket part are designed to fit around a plate holder part.