This is a portable pre-amp I build with reloadable battery built-in and it has a charger you can plug in when coming back home after the show to reload your battery. The pre-amp is specially designed to be robust and light, with a nice metal box, for cigar box guitars piezos and pickups, so you can get a great sound to send into your amplifier. The pre-amp have an input for the guitar, an output for the cable going to your amplifier, and also an output for a headphone ! When using the headphone you can play without disturbing anyone and you don't need your big amplifier, still you will get the great sound coming out from your lovely cigar box guitar :-) There is also a on/off switch so you can save your high quality battery when needed and it will last a very long time. The power plug is a special one so you will not confuse with anyother cables you may already have. I have some in stock that I can sell, and I often build some electronics for friends, so if you need one of these, feel free to send me a message.