HTC One X 16GB Unlocked GSM 4G LTE Dual-Core Smartphone - White 2G: GSM 850 / 900 / 1800 / 1900, 3G: HSDPA 850 / 1900 / 2100, 4G: LTE 700 MHz Class 17 / 1700 / 2100 4.7-inch Super IPS LCD2 Multi-Touchscreen w/ HTC Sense UI and Corning Gorilla Glass Dual-HD Camera; 8 Megapixel Rear Camera + Font-Facing 1.3 Megapixel Camera Dual-Core 1.5 GHz Krait Processor, Chipset: Qualcomm MSM896 Snapdragon, Adreno 225 Graphics Internal Memory: 16GB, 1GB RAM (memory not expandable) 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.