This thing replaces part "E" ("wooden panel with adjustable level screws") of the Z-Stage in the original Ultimaker. Several years ago I installed a heated bed that consisted of a heavy hunk of aluminum, which not surprisingly is stiffer than the flimsy birch panel that was supporting it, so over time the panel warped. This is my replacement because I'm too cheap to spring for the Ultimaker+ upgraded z-stage, which is very nice I'll admit.If you are using a heated bed, don't print this in PLA because it will soften up from the heat and sag like an old lady. I recommend PET if you have it, but ABS will work too if you are skilled at fighting the dreaded warp factor. Don't be stingy with the infill. Hopefully the installation is self-explanatory. Use the same screws, but you don't need the nuts because the screws will thread into the brace. Do not over-tighten.