Samsung I8552 Galaxy Win 4.7-Inch Quad Core Dual Sim 8GB Android Smartphone (GSM Factory Unlocked) Samsung I8552 Galaxy Win, Unlocked 4.7" Dual Sim 8GB Android Smartphone- White 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.