Commissioned from a famous artist. This is a custom-made, handmade line selector/switcher. It allows you to select between A and B systems, or output both A + B simultaneously with a switch. It's very convenient for separating amp output and line output. DC9V specification. Operation has been confirmed, and there are no functional issues. I believe this compact product with these specifications is quite rare on the market. Don't miss this opportunity. #Multieffects #AmpSimulator #Preamp #GuitarAmp