About this 3D model

The Meissner Tetrahedron is a body of constant width. That means, you can use it to roll a plane on it like on a ball, and the distance keeps the same. From the look of the somewhat irregular shape you might think that would be a bumpy ride, but it ist not! Here's a nice explanation on those bodies: http://www.youtube.com/watch?v=cUCSSJwO3GU