Yooperlite Oloid

The surface of the oloid is a developable surface, meaning that patches of the surface can be flattened into a plane. While rolling, it develops its entire surface: every point of the surface of the oloid touches the plane on which it is rolling, at some point during the rolling movement.

This is different in, for example, spheres such as marbles.

Includes UV torch to highlight the fluorescence.