AT&T Branded but is ALSO unlocked for all GSM carriers worldwide (i.e. carriers that use a SIM card), like T-Mobile, H2O, etc. LTE Band include: 1, 2, 3, 4, 5, 7, 8, 12, 20, 29, 30, 38, 39, 40, 41;Built-in, defense-grade mobile security with the industry-trusted Samsung Knox platform;Powerful productivity features so you can work on the move, all day long, on the stunning 5.1-inch Super AMOLED Display;Light, sleek, elegant design with an all-glass-and-metal chassis that reflects the quality of your organization;Internal Memory: 32 GB, 4 GB RAM (memory not expandable)