HTC One M8 Dual-SIM 16GB Unlocked GSM 4G LTE Quad-Core Android Smartphone - Silver 2G: GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2, 3G: HSDPA 850 / 900 / 1900 / 2100, 4G: LTE 800 / 900 / 1800 / 2600 5" Super LCD3 Capacitive Multi-Touchscreen w/ Protective Corning Gorilla Glass 3 Android v4.4.2 KitKat (upgradableable), Quad-Core 2.3 GHz Processor, Chipset: Qualcomm Snapdragon 81, Adreno 330 Graphics Dual 4 Megapixel Cameras (2688 ? 1520 pixels) w/ Dual-LED Flash + Front-Facing 5 Megapixel Camera Internal Memory: 16GB, 2GB RAM + microSD Slot Expandable up to 128GB 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.