Flag
http://www.mahq.net/mecha/gundam/00/svms-01.htm
Assumedly grunt unit with no info yet.
http://www.mahq.net/mecha/gundam/00/vms-15.htm
I made an assumption based on a few stuff that it was a protoype. 1stly the model number is -01....which usually means its an advanced prototype. The pilot also is Graham Acre meaning its one of a kind currently. In episode 3 between Graham and that scientist guy, he mentioned that he lost his rifle and has to do a report for it, (probably the linear rifle is a new thing for the Union since the green grunt units were using machine guns) then the scientist says that it was still advantageous if they lost the whole Flag for data on the Gundams, so the Flag has to be special in some way.
Notice too that the mobile armour mode for the Flag and the grunt units that engaged Exia have a slightly different look. But I'm not sure if the guy in the light green mobile suit in episode 1, if that's a Flag another one because Graham and scientist guy did say that it was exactly like "theirs" (i'm assuming the Flag) but with some minor cosmetic changes to its body and face. So i suppose that the light green one will be the mass production model which was based on the Flag.