2,4,8,16,32,64. Though clearly a (very excellent looking) die, with each side a mathematical doubling of the next, I did not know exactly what this was when I found it. Didn't take long to learn that die like this were and are made for use in backgammon-- specifically for raising (doubling) the stakes in a game.  I've learned with a bit of research that the first doubling cubes were introduced in 1930, and this is an iconic very early example, perhaps the very first to be produced. Made of bakelite, with the engraved numerals filled with a white inlay material so to be flush with the surface of the cube. Here is a link to a page on the website of the New England Backgammon club devoted to the history of doubling cubes, with a photo including this specific cube. These early examples appear to have become quite precious--a perfect gift for a backgammon aficionado, but also just a great, and very graphically satisfying object.

1 3/8" cubed. Very good condition, reads crisp and sharp, with minor loss of white inlay in a couple of spots (mostly on the 4).