What is the name of this model?

There's a model/artwork/experiment where two plates are stacked on top of each other, and the upper plate is attached to the lower plate with a chain at the four corners. The upper plate should actually fall off, but because there's another chain (with supports at the top and bottom) attached in the middle between the upper and lower plates, holding everything together (and now the upper plate is "hanging" from the lower one), it looks as if the outer chains are holding the model by themselves. But they're only there to hold it together so the upper plate doesn't slip. Here's another picture of the side view. Can someone tell me what it's called? Thanks 🙂