TTONE Hand Made ABY Selector Combine Pedal Guitar Switch Box TRUE BYPASS Amp Guitarra Pedals AB/Y The ABY footswitch can be used to solve any number of complex audio switching problems. Use it to switch one input signal to either or both outputs, or it can also be used in the opposite direction. Route one signal to two outputs or two inputs to one output. Then choose A, B or A & B combined. LED's show you which signal is active. One 9 volt battery is required for LED indication.(battery is not including in package)