Features: Glasses: Lens of baolilai from America company TR 90 Frame Shock proof and Anti-static electricity Audio: Compatible format: MP3, WMA, ADPCM 3D Stereo Sound Integrated Microphone supporting ADPCM recording. Five different Equalizer modes Voice output power: 5mW + 5mW Voice output frequency: 20Hz ~20KHz Memory storage: Available flash memory size: 64MB, 128MB, 256MB, 512MB, 1GB Standard USB 2.0 port Integrated USB drive Share same USB port for Download, Upload and Recharge Battery: Continuous playing time: 7 hours Recharging time: 3 hours 460mAh / 3.7V macromolecule polymer Li-ion recharging battery Automatically detected battery voltage and capacity Battery consumption saving function