Cat - S50 8GB Unlocked GSM 4G LTE Military Grade + IP67 Quad-Core - Black 2G: GSM 850 / 900 / 1800 / 1900, 3G: HSDPA 850 / 900 / 2100, 4G: LTE 800 / 850 / 900 / 1800 / 2100 / 2600 (Bands 1, 3, 5, 7, 8, 20) IP67 certified & MIL-STD-810G certified; dust and water proof, Drop-to-concrete resistance up to 6 feet Android v4.4 (KitKat), Quad-Core 1.2 GHz Cortex-A7 Processor, Chipset: Qualcomm MSM8926 Snapdragon 4, Adreno 305 Graphics 8 Megapixel Camera (3264 x 2448 pixels) w/ Autofocus & LED Flash + Front-Facing VGA Camera + Video 1080p@30fps Internal Memory: 8GB, 2GB 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.