It is not uncommon for guitarists to use more than one guitar amp. Often, one guitar amp is good for lead sounds but not so good for rhythm use. This is one situation where a guitarist can choose two different amps for different roles, and this is where an ABY-1 switcher box is essential.
Sometimes a guitarist uses two guitars and needs to select between them when using a single amplifier. ABY-1 can be used for this purpose too.
ABY-1 uses conventional ‘latching' switches to perform the functions and requires a 9V battery to power the LED status indicators. The battery is exclusively to light the LEDs, so you can use it just the same when the battery has run down.