Unlocked cell phones are compatible with GSM carriers like AT&T and T-Mobile as well as with GSM SIM cards (e.g. H20, Straight Talk, and select prepaid carriers). Unlocked cell phones will not work with CDMA Carriers like Sprint, Verizon, Boost or Virgin.
The Nokia Lumia 900 comes as one of the first Windows smartphones to support LTE connectivity. It also sports a magnificent 4.3" AMOLED display.