Sony Ericsson Xperia arc S LT18a Unlocked Phone with Android, 8 MP Camera, 1.4 GHz Processor, and 4.2-Inch Display--U.S. Warranty (Black) Video calling General 2G Network GSM 850/900/1800/1900 Display Type LED-backlit LCD, capacitive touchscreen, 16M colors, Size 480 x 854 pixels, 4.2-Inch (233 ppi pixel density) 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.