... ,USB Portable SD/TF/USB/MMC Cards MP3 Player/Speaker HOT1)ROHS,CE,FCC 2)With ... notebook computers, mobile phones, MP3, MP4, DVD, CD, U plate and the audio equipment outside put.2. ... stereo headphones plug, USB interface(card reader)Adjust the volume, form: bass volume knob regulationBass unit: ... 5 inches (131 mm), the outer diameter magnetic, 4 ohmTweeters: 2.75 inches ...