5.7 inches 1440 x 2560 pixels (~515 ppi pixel density), Secondary display, 160 x 1040 pixels, 2.1 inches, Fingerprint Sensor (rear-mounted);64 GB ROM (~50GB after OS), 4GB RAM, microSD, up to 256 GB (dedicated slot) ,CPU Snapdragon 808 Hexa-core 1.2 GHz;16 MP, f/1.8, laser autofocus, 5 MP Front Camera, Android OS, v5.1.1;4G LTE band 1(2100), 2(1900), 3(1800), 4(1700/2100), 5(850), 7(2600), 12(700), 29(700), 30(2300) 3G bands HSDPA 850 / 1700(AWS) / 1900 / 2100;AT&T Unlocked Phone compatible with GSM SIM cards in U.S. and worldwide Including AT&T, T-Mobile, MetroPCS, Etc. Does not have US warranty. Will NOT work with CDMA Carriers Such as Verizon, Sprint, Boost.