After some justified criticism about the readability of my previous design for a Kaladesh energy die, I have made a redesign for it. The overall design is the same, but the numbers on the sides are a lot better to distinguish.
You can use this spindown d12 to keep track of the number of energy counters you collect when playing the Kaldesh expansion for Magic: the Gathering.
This die pictured is 3d printed in steel, but it is also available in a range of other finishes. It is part of a set of dice designed in the Kaladesh look.