slide nut / t-nut M4 for 3030 extrusion (e.g. Prusa MK3)

This is a simple M4 sliding nut (t-nut) for 3030 extrusion profiles like those used on the Prusa MK3/MK3s.
It is pretty rigid and way cheaper than aluminium ones.
You can use this to attach all kinds of things to the extrusions.

Requirements:
1x M4 nut