Samsung Ativ S Neo I187 16GB Unlocked GSM 4G LTE Windows 8 Cell Phone - Blue 2G: GSM 850 / 900 / 1800 / 1900, 3G: HSDPA 1900 / 2100, 4G: LTE 1900 4.77" TFT Display Capacitive Multi-Touchscreen Microsoft Windows Phone 8 OS, Dual-Core 1.4 GHz Krait Processor 8 Megapixel Camera (3264 x 2448 pixels) w/ Autofocus, LED Flash + Front-Facing 1.2 Megapixel Camera + Video Internal Memory: 16GB, 1GB 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.