PANASONIC GD55 GREEN (UNLOCKED TRIBAND)WORLDS SMALLEST GSM CELLPHONE GSM 900 / 1800 / 1900 THIS PHONE WILL WORK WITH T-MOBILE AS WELL AS WITH THOSE GSM CARRIERS WHICH OPERATES ON 1900Mhz.PLEASE CALL YOUR CARRIER BEFORE BUYING THIS PHONE SMALLES SIZE. SMS, TEXT MSG. PHONE BOOK.RING TONE. KEYPAD LOCK HELPS PREVENT ACCEDENTAL SETTINGS CHANGE,