... ,ROHS,ISO etc 2,professional amplifier,with USB,TF,MPS input 3,several colors ... move around your stage or classroom at your will with no leads or cords attaching you to one ... to use, can make MP3 player With USB,SD/MMC MP3 input With echo function Audio Amplifier Technology:Audio amplifiers feed ... Charger 1 x Manual 1x Cable 1x Color box With ISO,CE,ROHS etc certificates Portable Voice Amplifier ...