This is a modified version of the http://libre3d.com/category/511/Frames/listings/1077/Cubicle-Wall-Shelf.html
item. The other one didn't work out the way I wanted it to, so I modified the SCAD to make it fit my cubicle wall as well as making either side be able to fit. So it can hold the shelf or hold the wall.
If you would like to change up the sizes in the SCAD. Line 31's 2nd parameter modifies the height of a hook, and line 15 modifies the size of the grip. Depending on how you modify the size of the grip, you will need to translate the hook part to fit your grip.