... microphone,reverb used for teching and so on Specification:Multifunction all in one with Entertainment,Microphone, Amplifier, Loudspeaker,Music play and FM ... 4 V/ 2000 mA Battery working time Keep working in 7-8 hours Function Mp3, FM radio, Amplifier, Line ... -in, loudspeaker, microphone, reverberationColor ChoiceBlackWeight 0.5kg ( including battery ) ...