Here are the specs for the individual orb components.  Feel free to copy or scale this if you would like to fabricate one yourself.

Plans  

Interlocking orbs of stainless steel.  Made from 12 identical precision-cut components. Cut on a wire EDM machine and assembled by hand.  Sold in sets of
three, fully assembled.  1.9" diameter.  $85 per set

Stussi Balls

X12