This cell phone is compatible with GSM carriers like AT&T and T-Mobile as well as with GSM SIM need cards (e.g. H20, Straight Talk, and select prepaid carriers) need to contact the service provider to check fully compatibility of the phone.This Unlocked cellphone will NOT work with CDMA Carriers like Verizon, Sprint, Boost mobile or Virgin mobile.2G: GSM 850 / 900 / 1800 / 1900, 3G: HSDPA 850 / 1900 / 2100, 4G: LTE 700 / 850 / 1700 / 1800 / 1900 / 2100 / 2600Internal Memory: 16GB storage, 2GB RAM + microSD Slot Expandable up to 128GB5.1