... hours Battery working time keep working in 8-12 hourse Function Mp3, FM radio, Amplifier, loudspeaker, microphone, reverberation Digital mini professional ... this mini amplifier box. We have other style that have function such as FM Radio, USB/TF/MMC input ,music reverb ... .Please feel free to tell me if you like more function, I will recommend you as your request . Multi-function digital microphone