Sony Ericsson T637 Unlocked Cell Phone-U.S. Version with Warranty (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. U.S. version tri-band GSM cell phone compatible with 850/1800/1900 frequencies and GPRS capabilities VGA digital camera with screen viewfinder; up to 500 contact entries; 2 MB internal memory (not expandable) Speakerphone; Bluetooth for handsfree devices; access to personal email; organizer Up to 14 hours of digital talk time and 315 hours (13 days) of standby