Main display: PVI 6.0-inch SVGA EPD Backlight: no backlight without no any radialization Display size: 6-inch (800 x 600 pixels) Operating system: Linux 2.6 RAM memory: 128MB SDRAM Battery lifespan: 8,000 screen refresh (estimate 3 months based on reading speed of 500 pages per week) I/O: 3/5mm stereo audio jack for earphones USB port Connectivity: HS USB client Built-in Wi-Fi (IEEE802.11b and g) (optional) Storage memory: SD card (up to 4GB, supports SDHC) Format supported (with cyrillics supported): PDF, TXT, CHM, FB2, RTF, TCR, PDB, OEB, HTM, PRC, HTML, EPUB, DJVU, IW44, IW4, and DJV Audio format supported: MP3 , WMA Font size changing function: three sizes Indication: yes Languages: English, French, Chinese simplified, and Chinese traditional (can be customized)