The Hoberman Mini Sphere is a colorful, expanding and clever piece of engineering. It is an amazing fidget toy, and learning tool that entertains for hours. Expand the sphere and see how it works, roll it, touch different parts and see how they contract or stabilize. The sphere measures 5.5 inches across but can expand to 12 inches in diameter. The inventor calls it a trapezoidal icosatetrahedron. An enclosed pamphlet describes various tricks you can do--if you're prepared to practice.
Recommended for ages 4+