I'm selling this item, which I unearthed from an old effects pedal case. I used this back in the day to run two amps at live shows. Operation has been confirmed with a 9V power supply. Please note that this item is sold as-is, as I am unable to compare it to a new unit regarding any potential crackling or noise. This is a multi-functional instrument/amp selector with adjustable volume. - Brand: BEHRINGER - Model: AB100 - Function: Instrument/Amp Selector - Output Terminals: OUT A, OUT B - Input Terminals: IN 1, IN 2 - Mode Switching: MODE switch - Volume: Volume control knob Thank you for looking.