The first Mission pedal and still one of our top selling products, the SP-1 has two output jacks, one for the expression pedal and one for the switch. The SP-1 can be used with compatible devices such as digital effects and MIDI controllers to turn effects such as a wah or vibrato on and off at the pedal itself. The SP-1 is compatible with many popular digital amps, effects and MIDI controllers including Fractal Audio Systems Axe-FX, FM3 and FC controllers and Voodoo Lab Ground Control Pro.