Portable wireless speaker Applicable to USB,SD/MMC card,computer,mp3,mp4,mobile,ipod, ... Digital MINI card small speakers-Stereo sound,ultra-low sound powered from the phone.-Support USB,SD card,computer,mobile ... battery.You can use rechargeable or external power adapter USB charging voltage of 5 volts.-Alloy,bass vigorous,high ... Hours6 watts20-20KH2>85dB1-2 hours4-5hours wireless USB laptop speaker