FCC documentation has spat up a mysterious label which looks just like the same product family as another LTE compatible device that was submitted by LG, the M13 with EV-DO, and probably the newly passes M4 is the same type of thing but swapping out 700MHzLTE and EV-do for AWS LTE reports engadget mobile.
AWS LTE is in the spectrum range of MetroPCS only, who have been strongly committed to the roll out of LTE for next year.
However, LG has made sure they have been rather meticulous in making sure nothing can be nailed down in the FCC documentation as to exactly what it is; however apparently there is brief mention of USB connectivity so this could possibly be a type of data modem.