The Expand-O-Stilt is a toy designed to teach young children the basic principles behind mechanical advantage. It is a series of levers, which attach to the child's foot via a standard step-in snowboard binding. Then, the child should be able to lift themselves into the "Up" position using the lift handle. This will be assisted by the tension spring in the central diamond linkage. Once in the up position, the stilts can be walked on, and with practice, even jumping should be possible- and large jumps at that. The market for this toy is mainly age 6 to 12. This is primarily because of the dramatic price increase that would result from the sort of materials and techniques needed to support a larger 14 or older child. Although the main teaching apparatus is clear-- i.e. an abundance of visible levers--the toy might also come bundled with a book which talked about the history of levers: Archemedes, the catapult, and an explaination of other everday uses of the simplest of simple machines.