... . apply to mobile phone,MP3,MP4,PC and other audio output devices. TF card mini speaker (metal).Play TF card, U disk ... be connected to the mobile phone, MP3, MP4, the PC and other audio output devices. Output power: RMS 3Wx2 THD = 10 ... / NW: 21.5/20.5KGSAccessories: USB cable, audio cable Portable Stereo speaker mobile phone, MP3, etc