Unlocked Samsung SGH-T199 QuadBand Global Ready Worldwide GSM Phone with Large Buttons , Web , 3G , Up to 144 Hours of Stand By and 1 Year Warranty Large Buttons NetFront 4.2 browser with 3G capabilities Operates on quad band GSM 850, 900, 1800, 1900 MHz and UMTS 1700/2100, 1900 MHz wireless networks .Unlocked to use with AT&T, Net10, H2O, RED POCKET, Ultra Mobile, T-MOBILE, SIMPLE MOBILE and many many more on supported GSM frequencies outside the U.S and WORLDWIDE! 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.