This is a z axis stabilizer for my Replikeo Prusa i3 Rework. I found that the z axis was bouncing during prints. This makes it rock solid. It bolts on to the top using the same bolts that hold on the z axis smooth rod supports. The bottom screws into the board that the printer is mounted on.
Requires one 5/16" x 36" rod cut in half, 8 nuts, and 4 screws.