Thanks for asking. That is a Dice Labs D120. Wired magazine published a pretty good article on it a while back. Here's the link:
Here's a paper on how the numbers were balanced:
http://www2.oberlin.edu/math/faculty/bosch/nbd.pdf
And here's a YouTube video:
None of those links refer to my own work.
I want one of these!
You can buy one, or five, at MathArtFun.
http://mathartfun.com