A humbucking pickup, or humbucker is a type of electric guitar pickup that uses two coils to "buck the hum" (or cancel out the interference), induced by the alternating current in single coil pickups. Most pickups use magnets to produce a magnetic field around the strings, and induce an electrical current in the coils as the strings vibrate (a notable exception is the piezoelectric pickup). Humbuckers work by pairing a coil with the north poles of its magnets oriented "up", (or toward the strings), with a coil which has the south pole of its magnets oriented up. By connecting the coils in series and out of phase, the interference is significantly reduced via phase cancellation.