BLU Studio Energy 2 - 5000 mAh Super Battery - 4G LTE GSM Unlocked - Grey Refer the user manual below for troubleshooting CNC Machined out of one solid piece of aircraft grade aluminum to minimize all plastic parts, resulting in a remarkably high end uni-body device that leaves a lasting impression and unique feel in hand 5.0" HD AMOLED LCD, 8MP Main Camera + 5MP Front Camera, MediaTek Quad Core 1.3GHz Processor Unlocked Dual Sim Phone, Android 5.0 Lollipop, 16GB Internal Storage 1.5GB RAM with Micro SD Slot up to 64GB 4G LTE, (2/4/7/17),4G HSPA+ (850/1700/1900/2100). GSM Quad Band: US Compatibility Nationwide on all GSM Networks including AT&T, T-Mobile, Cricket, MetroPCS, Straight Talk, Pure Talk USA and others