Features and specifications: 1) Polarized lens and TR 90 frame 2) Compatible formats: MP3, WMA, ADPCM 3) Available flash memory size: 64MB, 128MB, 256MB, 512MB, 1GB 4) Standard USB port 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 supporting 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) Voice output frequency: 20Hz ~20kHz Inner packing: 1pc/gift box Outer packing: 50pcs/ctn Carton dimensions:50x36x42.5CM G.W.:12.8kg