Hi; I have a Boss JS-10 practice/jam "amp" for sale. I've had it for several years, but rarely used it as the JS-8 was fine for my purposes. The package is complete, works well and in really good shape. It is difficult to describe what this thing does, so I will provide a link to the Boss website that describes it far better than I can. If you are a guitarist that wants to significantly improve their "chops" this is an excellent tool. Thanks for looking. https://www.boss.info/us/products/eband_js-10/