Sony Ericsson X10 Mini E10i Black Unlocked Android Phone (Internation Version No US Warrenty) 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. This cell phone may not include a US warranty as some manufacturers do not honor warranties for international version phones. Please contact the seller for specific warranty information.