Samsung GT-I8150 Unlocked Cellphone - No Warranty - Soft Black 3.7-inch Touchscreen display Android 5MP Camera A-GPS Geo-tagging 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.