I hope this goes to someone who loves BOSS. I bought this used because I like BOSS, and I've kept it because I like the look of it, but it's a waste not to use it, so I'm putting it up for sale. It's an old item, so please assume there are scratches on the main unit, box, instruction manual, etc. 4-channel mixer It operates only on a 9V battery. I have confirmed that it works, but if any problems are found during the operation check before shipping, I may have to cancel the sale. BOSS Mixer Effects