1) Capacity: 1.8 inch 20GB HDD 2)Interface: High speed USB 2.0 (compatible USB 1.1) 2) Photo viewer: JPEG、BMP format 3) Video : MPEG-4 with MP3 near DVD quality ,AVI file format. Compatible XviD and DivX 4.0 & 5.0. 4) Audio: MP3 ，WMA ，WAV 5)Audio recording: Stereo WAV format 6)Battery playing hours: Approx 6 hours for music or 3 hours for video 7) Power source: built-in rechargeable Li-Ion Battery. 8)Dimension: 121 X 77 X 23.6mm 9) Weight: 265g 10) System requirements: PC: Pentium? II 400 MHz or higher, Windows 98 SE, ME, 2000 or XP. 64 MB RAM (128 recommended) with USB port and CD-ROM drive. MAC: 9.2 or X(10.2.4) USB Manager version 1.2 or higher with USB port and CD-ROM drive 11) Display: 3.5" TFT LCD, 480*360 resolution and TV output 12) Accessories: USB 2.0 cable, Stereo headphone, Installation CD, Manual, AC adapter