Purpose 

These two inserts are made for half inch (12.7mm) drive ratchet sockets. The inserts fit in the drawers of the StackTech drawer units. Because the outer diameters of sockets varies, I am including the source code for you to make adjustments to the hole sizes needed for your sockets, that may be different than mine. The sockets I used to define the sizes for these units are all Craftsman sockets from the 1980s and 1990s. I have a few other sockets (Kobalt, Snap-on, and “whatever Advance Auto sold that day I
needed one”), and mostly they fit, too. 

That said, your sockets may not fit so well; I therefore tried to make the OpenSCAD code easy to modify. 

Careful observers will note there are two 10mm socket locations. This feature is not a mistake.