4040 profile t nut that accepts a normal nut and 4mm bolt.
Not for structural use at its plastic holding it together.
V2. Had to make the hole for the nut slightly larger and decreased the holesize for the screw a bit.
The author remixed this model.
accepts a 4mm screw and nut instead of 3mm.
The tube on top is also shortened a bit so i could tighten it properly on my profiles.