The M-Audio EX-P expression controller pedal works with all M-Audio MIDI controllers that have an expression pedal input. Feel the need to express yourself fully? This pedal has a built-in polarity switch that insures compatibility with most other brands of controllers and keyboards. Use the EX-P to control any assignable variable MIDI controller value including volume, modulation, panning, filter sweep and more. Durable molded construction with integral cable. M-Audio EX-P Features Polarity switch Hardwired quarter-inch cable Molded construction