Samsung Galaxy S Duos II S7582 DUAL SIM Factory Unlocked International Version - Black Cellular Band - Quad-Band 850 / 900 / 1800 / 1900 Mhz Cellular Band 3G - 850 / 2100 Mhz Unlocked cell phones are compatible with GSM carriers such as AT&T and T-Mobile, but are not compatible with CDMA carriers such as Verizon and Sprint. 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.