For convenient music consumption during summer, this is absolutely ideal! The MP3 player doubles as a pair of sunglasses, and is lightweight enough to be comfortable for long-term wear. The battery is nothing to laugh at, either � 5 hours of unstopped music is enough for almost anyone!4GB Of Memory: A large capacity for such a slim model, this player will hold a large amount of data. To give you an idea, it can store and play approximately 1400 songs!Supports Most File Formats: The most common audio file formats (MP3, WMA and WAV) are all supported by this player, so there is no need to convert the music files you already have on your computer.Specification:RELATIVE TECHNOLOGY PARAMETER?Digital formats supported:MP3/WAV/WMAPC interface supported:USB2.0Mfr estimated battery life:5 hoursBattery tape/capacity : Bullt-in Lithium lon Polymer/3.7V.150mAHMaximum input power rating:5VDC Earphone output power:5mw Voice output frequency:20Hz-20KhzTHD:0.05%Recharging time:2 hoursNormally works current:30-35mA.Signal-to-noise ratio:87.2dbEarphone impedance :16 Weight:52gDimensions:17240mmExtended Length of Earphonefixed lever:14mmRotary degree of earphone fixed lever:270�Rotary degree of earphone:90� Condition: New