Ok,i just received this phone that it was supposed to be fully unlocked.With an unknown X SIM..atleast that ive never seen before.I was wondering out of curiosity which one is it?,does it has any official site or something?

On the other side of the SIM,it reads Free SIM HW3.0 MTSS.
of course it is supposed to be a free sim,but its just i dont remember seeing it.