UNLOCKED BLACK/SILVER LG Optimus Chat LG-C555 3G Phone, Slide Out QWERTY Keyboard, 3MP Camera, Google Android, BULK PACKAGED, 2G GSM 850/900/1800/1900MHZ, 3G HSPA 850/1900MHZ 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.