Features: 1) Polarized lenses (anti-scratch) and TR 90 frame 2) Available flash memory size: 128MB, 256MB, 512MB, 1GB 3) Compatible format: MP3, WMA, ADPCM 4) Standard USB port: USB 2.0 (full speed) 5) Integrated USB drive 6) Play function: play in order, pause, resume playing 7) Delete function: delete current or all songs or recordings 8) Integrated microphone supports ADPCM recording 9) Continuous playing time: 8 hours 10) Recharging time: 2 hours 11) 230mAh / 3.7V macromolecule polymer li-ion recharging battery 12) Automatically detected battery voltage and capacity 13) Battery consumption saving function: a) Automatic power off if no button pushed in 2 minutes under pause status b) Automatic power off in 2 minutes when all tracks played 14) Voice output power: 5mW + 5mW 15) S/N ratio: 80dB 16) Working temperature: -5 - 50°C 17) Earphone output: 5mW + 5mW 18) Frequency response: 20Hz - 20kHz 19) Sampling frequency of voice recording: 8kHz 20) Compression level: 32Kbps - 320Kbps 21) Share same USB port for download, upload and recharge 22) Lead time: 20 days after all order details confirmed Packing: standard export packaging