Sony Ericsson Z550a Unlocked Cell Phone with Camera, Media Player, M2 Memory Slot-U.S. Version with Warranty (Sterling Black) This unlocked cell phone is compatible with GSM carriers like AT&T and T-Mobile. U.S. version tri-band GSM cell phone compatible with 850/1800/1900 frequencies and GPRS/EDGE capabilities Clamshell phone with dual screens; 1.3-megapixel digital camera with 4x digital zoom Bluetooth for handsfree devices; Memory Stick Micro (M2) expansion; digital media player Up to 5 hours of digital talk time and 320 hours of standby time