... .USB laptop speaker 2.Audio speaker 3.Applicable to USB,SD/MMC card,mini TF 4.card,computer,mobile,MP3,MP4,Ipod ... ,PSP,MP3,MP4 to listen to music-Have audio interface,can do computer speakers -Power supply:Built-in 800 MAH,3 ... appearance cabinet and delicate your MP3, MP4, CD or notebook computer audio etc. For better efficacy. Reference coefficientOutput powerFrequency responseSNRCharging timeWorking ...