TTfone Pluto Big Button Clamshell Flip Mobile Phone - Easy to Use Simple Unlocked Sim Free - Black Clamshell Flip Design - Avoid accidental pocket dials Bluetooth connectivity Big Buttons and Loud volume SOS button for emergencies Unlocked - Please note this phone will not work on the Three network as it is not 3G 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.