Not much to say about this one. It's a 4x1 Gridfinity base that can be attached to a Skadis Shelf.

The 3mf file already contains the two hooks you'll have to press-fit or glue into the pockets on the back side. For those who prefer to print the STL directly, all files for those hooks (STL, 3MF, FreeCAD) have also been attached.

The screws are optional and only make sense if you use Gridfinity bins with magnets on the bottom. In that case, either M3x4 or M3x6 will fit fine. You should make sure to get screws that are actually magnetic, which stainless steel ones typically aren't. I personally use these: https://amzn.to/42u7m3L (Amazon DE affiliate link).