BLU Advance 4.5 Unlocked Dual SIM Phone (Black) Unlocked Dual SIM Phone, Dual Core 1.0 GHz Processor Android 4.2 Jelly Bean, 4G 850/1900 HSPA+ 21 Mbps 4.5" High Resolution FWVGA Display 3.5 mm Audio Jack, FM Radio, MP3 Player, MP4 Player Micro SD Slot up to 32GB 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.