I snapped up a bunch of those a few years ago. My favourite cups.
But there are two different kinds. I "believe" that the one you've shown is the older model. The newer (and I "believe" they are) model has a much flatter bottom. The one you've shown has very little of the bottom that actually makes contact with a surface, making it very tippy. The newer ones are also a softer plastic, and a slightly lighter shade of OD.
The one to the right is army issue. /Mimung
Edit: Spelling....