1.USB laptop speaker 2.Audio speaker 3.Applicable to USB,SD/MMC card,mini TF 4.card,computer,mobile,MP3,MP4,Ipod iphone etc. Digital MINI card small speakers-Stereo sound,ultra-low sound powered from the phone.-Support USB,SD card,computer,mobile phone,IPOD,PSP,MP3,MP4 to listen to music-Have audio interface,can do computer speakers -Power supply:Built-in 800 MAH,3.7-volt lithium battery.You can ...