Mobiper W8 Smartphone 5.5 Inch Android 4.4 MTK6582 Quad Core QHD Screen OTG Dual SIM 3G WCDMA unlocked Smartphone AT&T straight talk net10-black Unlocked world GSM phone. 3G-850/2100, 2G -850/900/1800/1900 Compatible with at&t, T-Mobile, Straight Talk, Simple Mobile and other GSM networks Please make sure your SIM card is not locked with PUK code from your carrier 3G HSPA+ - 850/2100 bands. Fully compatible with AT&T, Stright Talk(AT&T Tower) & Net10 (AT&T Tower) at 3G HSPA+. Compatilble with T-Mobile, ------&gt;Simple Mobile, Straight Talk(T-Mobile Tower) & Net10 (T-Mobile Tower) at 2G (EDGE). For Straight Talk, Simple Mobile or Net 10 will require a manual APN setup Dual Sim card slot.one for standard SIM card .one for micro SIM card. 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.