The the first and most popular Mission Pedal. The SP-1 is an expression pedal with a switch. The switch sits under the pedal and is operated by pushing down on the front with your foot in the same way as a traditional analog wah pedal. Typically this is used to turn a pedal driven effect such as a wah or vibrato on an off at the pedal itself. There are two quarter output jacks, one for the expression pedal and one for the switch.