There are specific screen protectors for O4X, just google it, try the tags "P880 screen shield" or something like that...
http://www.tvc-mall.com/details/LG-Optimus-4X-HD-P880-Screen-Protector-Film-MPS-P880-01/
those are not the same, they scratch very soon.
The one I want is not totally hard, has some viscosity and does not scratch, and is thicker for hits, so I like it.