This is likely a discontinued LINE6 filter effects pedal. I've confirmed that it produces sound and the effects work, and that the memory functions. However, since it's an older unit, I haven't been able to check every detail. Although not an original accessory, I will include a LINE6 AC adapter that is likely compatible. (This was included with another unit in this series or a POD.) I haven't checked whether it can be powered by batteries. Please note that there is no box or manual. - Model Name: FM4 Filter Modeler - Function: Programmable filter and microphone synthesizer - Memory: 4 memories - Effects: 16 vintage and new effects - Connection Type: True bypass - Included: Power adapter and manual - Construction: Rugged construction Thank you for looking.