karaoke system 1.with USB/MP3, SD card &recording functions multy functions. ... with USB port and SD card reader,use Lithium-electricity rechargeable battery.can wear it,belt it&waistband, easy to carry ... use of simple and low cost, schools, outdoor lectures, dance,tour guides,Conferencing,Picnics,Trad show promotions,Coaching, gymnastics demonstrations, outdoor ...