WOWee One Slim Portable Speaker for iPad, iPhone, MP3 Players, Laptops, Mobile Phones, Personal Game Systems (Black/Chrome) The WOWee ONE Slim rechargeable speaker is fun to play with, and if you like to take your tunes on the road and travel light Internal battery up to 10 hrs play time per charge Rechargeable via USB Incredible bass 40 Hz - 20kHz sound range LED battery low indicator