Nokia Lumia 520 Quad-Band GSM Unlocked Smartphone - Blue 4" IPS LCD capacitive touchscreen, 16M colors 5 MP (2592&#x445;1936 pixels) camera w/ autofocus, geo-tagging 720p HD Video Capture Dual-core 1 GHz CPU featuring Qualcomm MSM8227 processor Microsoft Windows Phone 8 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.