Unlocked cell phones are compatible with GSM carrier such as AT&T and T-Mobile, but are not compatible with CDMA carriers such as Verizon and Sprint.  Please check if your GSM cellular carrier supports the bands for this model before purchasing, LTE may not be available in all regions: FDD-LTE (Bands 1, 2, 3, 5, 7, 8, 18, 19, 28) TDD-LTE (Bands 38, 39, 41) WCDMA (Bands 1, 2, 3, 5, 6, 8, 19) GSM/EDGE (850, 900, 1800, 1900MHz)  . OS: ZenFone 5 with Android Oreo and new ASUS ZenUI 5, Chip: Qualcomm SDM636 Snapdragon 636 Octa-core Kryo 260, CPU ; 64GB ROM, 4GB RAM ; Supports microSD, up to 2 TB (uses SIM 2 slot) ; 3300 mAh battery. Main Camera: Dual: 12 MP, phase detection autofocus, OIS, LED flash; Front Camera: 8 MP. Display: 6.2 inches, IPS LCD capacitive touchscreen, 16M colors. This device may not include a US warranty as some manufacturers do not honor warranties for international items. Please contact the seller for specific warranty information.  The box contains: Your new device, USB cable, Earphones, Charger (may be foreign), Documentation. The artificial intelligence (AI) inside every ZenFone 5 makes it more than just a smartphone: it’s your intelligent companion that’s always there for you. It takes perfect photos every time, whatever the subject, without you even having to think about it. No matter the task, ZenFone 5 always delivers smooth and responsive performance, with the striking compact design and stunning looks making it a sheer joy to use. ZenFone 5 is the smartphone that loves photos as much as you do!