This here is the Calabi-Yau Manifold Crystal.  To find out how it relates to string theory and the dimensions we humans cannot experience, read on:

According to string theory, space-time is not four-dimensional as you might expect, but actually 10-dimensional. The extra six dimensions are believed to be compactified or rolled up into such a small space that they are unobservable at human scales of sight. Their size and six dimensions make Calabi-Yau spaces difficult to draw. But, this model shows a three-dimensional cross-section of this likely space to reveal its structure and shape.

Oh, and it’s only $90 for that lucky physicist in your life, available here to purchase.

[Via Gizmodo; Scientifics Online]