Features: 1) File format: MP3, WMA 2) Frequency range: 20Hz - 20kHz 3) Bit rate: 8 - 320Kbps 4) SNR: 85dB (MP3) 5) Operating system: Pentium 133mHz or above, CD-ROM, 10MB free hard disk space 6) Windows system: Window 98SE/ME/2000/XP 7) MAC system : MAC OS 9.2.2 or above 8) Storage space: 64MB~1GB (optional) 9) USB port: USB2.0(full speed) 10) Playing time: <13 hours (MP3, 128Kbps, 44.1KHz) 11) Size: 151 x 148 x 73mm 12) Weight: 72g 13) Battery: 430mAh Li-polymer battery