It’s a novelty toy. There are perhaps 15 identical, wooden rectangular pieces, each of which have the length and width of a playing card and a thickness of about a quarter inch. They are linked together with tape so that they form a chain. When extended, it looks a little like the photo pouches in your wallet.

What makes this thing interesting is what happens when you hold it at one end and let it dangle vertically. When you take the top-most piece that you’re holding and flip it, folding its face into the block below it, a chain reaction happens. All the blocks below it flip in turn, one at a time, until the bottom-most piece flips. It’s a cool thing to watch, and it kind of reminds me of fans in a baseball stadium doing “the wave”. This chain of blocks is able to behave this way because of the unique way the blocks are bound together with the tape.

What in the world is this thing called???