I picked up a $1 hand-crank flashlight at a Dollar Store. I thought it would be a good teaching material for an introductory physics course. In particular, it contains a magnet and a coiled wire for generating electricity.
This is what the internal components look like. The handcrank turns the large gear.
The ring shaped magnet rotates by the hand-crank and a set of gears on top of a coiled wire.
Other interesting bits found inside were: a set of gears that makes the magnet rotate in one direction only.