BLU Studio C Mini D670L 4G HSPA+ Unlocked GSM Dual-SIM Cell Phone - Black 2G: GSM 850 / 900 / 1800 / 1900 (SIM 1 & SIM 2) 3G: HSDPA 850 / 1900 / 2100, 4G: HSPA+ 850 / 1900 / 2100 (not LTE) 4.7" IPS LCD Capacitive Multi-Touchscreen Android v4.4.2 (KitKat), Quad-Core 1.3 GHz Cortex-A7 Processor, Chipset: Mediatek MT6582, Mali-400 Graphics 5 Megapixel Camera (2592 x 1944 pixels) w/ Autofocus, LED Flash + Front-Facing 2 Megapixel Camera Internal Memory: 4GB ROM, 512 MB RAM + microSD Slot Expandable up to 64GB 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.