NP770Z5E - matte, silver (the one that I have)
NP780Z5E - glossy, touchscreen, silver
NP870Z5E - matte, black
NP880Z5E - glossy, touchscreen, black
The one that is talked here is the 770Z5E but gdgt specs are wrong cause that model doesn't have a touchscreen onboard.
You can also found it as the Ativ Book 8