New Asus Zenfone 5 8GB Dual SIM (Unlocked) A501CG 3G 5" Intel Z2560 1.6GHz Red Zenfone 5 8GB Red 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.