Factory Unlocked Samsung Galaxy Exhibit 4g (T599n) GSM Works Worldwide with any SIM Card UNLOCKED QUADBAND USE ANY SIM WORLDWIDE 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.