I wanted a more stable and secured way to build a shelving unit using the Multiboard system while leaving as much 'open' space on the sides. Thus, I spliced a 6x6 push-fit bracket and a 4x4 push-fit bracket together into this here thing.

This is made so I can put one Multiboard Plate on the bottom, and then on the top and bolt-lock them together.

You can find the 6x6 double bracket here: https://thangs.com/designer/Peter%20Krzyzek/3d-model/Multiboard%206x6%20Push-Fit%20Double%20Sided%20Bracket-1079038