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:

https://www.wired.com/2016/05/mathematical-challenge-of-designing-the-worlds-most-complex-120-sided-dice/

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.