Unlocked HTM A9500 Quadband Dual Sim Android 4.1 Os with 5 Inch Touch Screen Smart Phone - At&t, T-mobile, H20, Simple Mobile and All Other GSM Networks (Black) 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.