The EMG Pi2 is an active phase reversal circuit mounted on a mini-toggle switch, and is used in guitars with two or more EMG Pickups. Wired in series with one of the pickups, the Pi2 mimics "out of phase" sound by reversing the phase of your pickup. This active method of inverting the pickup's phase recreates that classic airy out of phase tone while maintaining the noise free operation of an EMG. It requires the same amount of space as a conventional phase switch, and thanks to EMG's solderless wiring, is easy to install on your own.