Chinese Finger Trap

This classic item, also called a “Chinese finger puzzle” or “finger cuff”, is a simple woven tube that humorously traps a person's two index fingers. The natural reaction—pulling the fingers apart—makes the trap tighten. It is usually made from thin strips of bamboo, paper, ribbon, or plastic woven diagonally into a hollow cylindrical braid. You insert one finger into each end.

Its operation is an elegant example of geometry and friction:

• Pull outward: the woven tube becomes longer and narrower, gripping the fingers more tightly.
• Push inward: the tube becomes shorter and wider, loosening its grip.
• To escape, you therefore push your fingers toward each other first, enlarging the tube, and then gently withdraw them.