Nokia Lumia 822 GSM  Verizon CDMA 4G LTE Windows Smartphone -Black 2G: CDMA 800 / 190 + GSM 850 / 900 / 1800 / 1900, 3G: CDMA2000 1xEV-DO + HSDPA 850 / 900 / 1900 / 2100 4G LTE: LTE 700 MHz Class 13 Microsoft Windows Phone 8 OS (upgradeable to WP8 Amber) 4.3" AMOLED capacitive touchscreen w/ Protective Corning Gorilla Glass 2 and Nokia ClearBlack Display 16 GB, 1 GB RAM + microSD slot expandable up to 64GB Unlocked cell phones are compatible with GSM carriers like AT&T and T-Mobile as well as with GSM SIM cards (e.g. H20, Straight Talk, and select prepaid carriers). Unlocked cell phones will not work with CDMA Carriers like Sprint, Verizon, Boost or Virgin.