The Bones Twin-City footswitch from Radial Engineering is an active ABY switcher and buffer that enables you to connect any two amps and drive them simultaneously without noise, loss of gain, and without degrading your natural guitar tone. This is accomplished with Radial's highly acclaimed buffering technology and the same Drag Control load correction circuitry as used in the award-winning Radial JD7 Injector. The 'set and' forget Drag Control lets you compensate for cable signal loss and introduce the perfect amount of loading to replicate the way your guitar and amp interact. To eliminate hum and buzz from ground loops, the Twin-City is equipped with an isolation transformer on output B.