The ABY Switcher allows you the ability to switch between 2 output or switch them on together.
If your setup is 2 amps, plug your amps into A and B then you can switch the output between the 2 or run them both at the same time.
This is an ABY switch which lets you send your input to either the A or B outputs, or to both simultaneously.
This ABY pedal comes with the added benefits of being active and having the B output going via an isolation transformer. With the pedal being active means that there will be no signal loss when the input signal is split to both outputs, and having output B going via an isolation transformer means there will be no ground hum issues. There are two toggle switches on the rear of the pedal, one that reverses the phase of output B incase there are any phase issues when using both amps, plus a ground lift so everything is covered!
The pedal is powered via the 9v Boss style 2.1mm DC socket (centre negative).