Sony XPERIA Z Ultra C6833 16GB Black (Unlocked International Model) Built-in Storage: 16GB Operating System: Android OS, v4.2 (Jelly Bean), planned upgrade to v4.4 (KitKat) Disclaimer: Please check if your GSM cellular carrier supports the bands advertised for this model before purchasing, LTE may not be available in the US as this is the international model. Compatible Carrier & Service: GSM 850 / 900 / 1800 / 1900 - all versions Form Factor: Smart Phones Dual SIM: NOT DUAL, Micro-SIM Touch Screen: Capacitive touchscreen Main Display Size: 6.4 inches