Sliding block nut for Geeetech A20M

To improve my new Geeetech A20M with a Raspberry Pi I've designed a new holder (https://www.thingiverse.com/thing:3470418) for the Anycubic i3 MEGA Raspberry Pi case for OctoPrint by FischC (https://www.thingiverse.com/thing:2754779).

I had the problem to fix it at the side of one profile because I didn't even know the name "sliding block nut", so it was very difficult to search for :)

That's why I've made one with FreeCAD. This part has not exactly the same size, because I've decided to