... power exausted. Long time battery lifeLine-in function, Compatible with all the devices that have 3.5mm plug. Spring column pops up, wonderful ... -Noise>80db6.Distortion<0.5%7.BatteryBuilt-in Li-Battery with circuit protection(300ma)8.Mains input5v/500MA Desk Lamp Mini ... ,loudspeaker, MP3 speaker,aluminium speaker,alumimium mini speaker Mini Speaker with Vacuum Bass