ZTE Open C Latest Dual Core 3G Firefox Os Android 4.4 Kitkat 3g 4.0" Unlocked Smartphone Firefox OS is the free and open source operating system from Mozilla. Its mission is to promote openness, innovation, and opportunity by keeping the power of the Web in your hands. Support 2G network: GSM 850/900/1800/1900MHz, Support 3G network: WCDMA 850/1900MHz 4.0 inch large TFT capacitive screen with 800 x 480 pixels WVGA screen resolution. 3.0MP rear camera, up to 1600x1200 pixels resolution Fiefox1.3 OS with 1.2GHz Qualcomm Snapdragon 200 MSM8210, Dual core processor and 512MB RAM + 4GB ROM Can reflash the Android 4.4 OS. If you are not accustomed to using Firefox OS, please contact us and we will provide you the Android OS firmware. If you reflash the Android OS, the Back Key and the Menu Key will be enabled without backlight 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.