BLU Win JR 4-Inch Windows Phone 8.1, 5MP Camera, Unlocked Cell Phones-Yellow 4GB Internal Storage 512MB RAM with Micro SD Slot up to 32GB Qualcomm Snapgradon 200, 1.2 GHz Quad-Core, Windows 8.1 OS 5MP Autofocus Camera with LED Flash, HD recording (720p), with VGA frontal camera 4G HSPA+ up to 42 Mbps 850/1900: Nationwide AT&T: Cricket Wireless, Straight Talk, Net10, H20 Wireless, 420 Wireless, Black Wireless, Consumer Cellular, Pure TalkUSA, Red Pocket, Telcel America. T-Mobile: MetroPCS, Lyca, Speedtalk, Go Smart, Simple Mobile, Net10, Straight Talk, Solavei, Ultra Mobile, Telcel Amrica, Walmart Family Mobile supported in most areas; check with your service provider; dual SIM 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.