Samsung Galaxy S4 I337 16GB Unlocked GSM 4G LTE Quad-Core Smartphone w/ 13MP Camera - Black (Certified Refurbished) Unlocked for all GSM Carriers Worldwide. 4G: LTE exclusively to AT&T (bands 17 / 1700 / 2100) 5-inch Super AMOLED Capacitive Multi-Touchscreen w/ Protective Corning Gorilla Glass 3 13MP Rear Camera (4160 x 3120 pixels) w/ Autofocus & LED Flash + Front-Facing 2MP Camera Quad-Core 1.9 GHz Krait 300 Processor, Chipset: Qualcomm APQ864T Snapdragon 6 Internal Memory: 16GB storage, 2GB RAM + microSD Slot Expandable up to 64GB