BLU Advance 4.0 Unlocked Cellphone, Black Unlocked Dual SIM Phone, MediaTek Dual Core 1.3 GHz Processor 4.0" High Resolution WVGA Display 3.5 mm Audio Jack, FM Radio, MP3 Player, MP4 Player Micro SD Slot up to 32GB Android 4.2 Jelly Bean; For any further queries please contact BLU Customer Support Number @1-877-602-8762 GSM Quad Band 3G/4G HSPA+ (850/1700/1900): US Compatibility Nationwide on all GSM Networks including AT&T, T-Mobile, Cricket, MetroPCS, Straight Talk, Pure Talk USA and others 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, Pure Talk USA and select prepaid carriers). Unlocked cell phones will not work with CDMA Carriers like Sprint, Verizon, Boost or Virgin. 4 GB Storage Capacity (Estimated Free Space 2.25 GB)