Designed by Chuck Hoberman, an artist, engineer and inventor, this is an unfolding, collapsible structure. The sphere combines math, geometry and aesthetics. It opens simply and is an educational experience. The Hoberman Sphere is also a sturdy art experience. Children like to wear it and move it. It packs well and is great to bring along when ttraveling. The Sphere is an enjoyable, stress-reducing, and innovative product. The sphere comes in different colors--silver, rainbow, glow-in-the-dark, multi-color--and expands from nine inches to 30 inches. You can watch it contract and get bigger and smaller.