The rack contains 32 pull-out shelves with 3 MacBooks each. It was put together for some kind of testing. It seems kind of extravagant, but when you want to get something done, sometimes the direct approach is quicker, easier, and in the long run, less expensive that trying to cobble something together with some off brand components. Via Detroit Steve, who is not the same Steve who built this thing, though they both live in the same city. How about that? Two guys named Steve living in Detroit. Who'd a thunk it?