Note these are factory seconds?? some units may have one or both line inputs not working. Get quality controlled version from here : https://www.amazon.com/Karaoke-Mixer-Microphone-Stereo-Balanced/dp/B01H66TT52</br>Full metal case. Runs for more then a week on a 9v battery (battery clip provided)?? or use wall AC/DC adapter (DC 9 to 20v?? 2.1 m