Samsung Shark 3 S3550 Unlocked GSM Slider Phone with 2MP Camera, Music Player, FM Radio and microSDHC Slot - Black This unlocked cell phone is compatible with GSM carriers like AT&T and T-Mobile. Not all carrier features may be supported. It will not work with CDMA carriers like Verizon Wireless, Alltel and Sprint. 2MP Camera; microSDHC Slot up to 8GB Stere FM Radio wityh RDS; Music Player SMS, MMS, Email, IM Standby up to 440 h; Talktime up to 9 h 50 min 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.