nextbook e book reader 1. Android OS, 7inch 2. Memory size optional 3.Wifi ... (dual core) 600MHZSDRAM2×64MBOSAndroid 1.5 Internal MemoryNAND Flash: 2GB,4GB,8GB,16GB(optional)Memory card typeSD card: 1GB,2GB ... ,4GB,8GBE-book Format EPUB,PDF,TXT,FB2USBHigh Speed USB2.0Recording , ...