Your Bag

This base is clearly designed for 1/100 (MG) scale models. Smaller models (1/144, HG, RG, EG) look a little out of scale. But it's not terrible. I use it for my HG models all the time.

Unlike some Gundam Markers, there are no warnings on the packaging specifying that they're not for use on ABS. Still, I'd test on a bit of runner just to make sure.