This handydevice allows you to send one guitar signal between two amps or activate both of them. Reverse the connections and you can switch between two guitars and a single amp. This is a no brainer, no frills box that works like a dream with a bi-amp stage setup. The switching is quick, clean and popless thanks to Whirlwinds patended optical system.. The footswitches are top notch but placed uncomfortably close together for most tapping toes. Positioning your foot just right to make the switch isn't always the perfect scenario on dark stages or for those inclined to gymnastic-like theatrics. If switching snafus do occur at least the highly visible LEDs keep you posted of the your status. Getting juice to the unit is through a single 9-volt or by an optional AC adapter.. This is one of the pricier boxes on the shelf but a real trooper that should last as long as you.