Unlocked 4 Inch 4GB Android Dual Core DualSIM GSM 2G+3G/A-GPS Smartphone ATT (Black) Operating system: Android 4.2.2 Dual Cameras, CMOS sensor provide good image quality, front camera 1.3MP, back camera 4 inch big screen, resolution: WVGA, 800x480 pixels MTK6572 Dual core CPU, 1.3GHz Smart phone, fashion design, multi-color back shell, dimension of 129.00*65.00*10.00mm 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.