Source Audio SA161 Dual Expression Pedal w/ 3 Free Cables Two Isolated TRS Expression Outputs - simultaneous control over multiple effect pedals or rack systems Sensor Output - 1/8-inch; four conductor output compatible with all Soundblox, Soundblox 2, or Soundblox Pro pedals Range Adjust Knob - Adjusts the range of expression signal sent through the outputs OUTPUT 1 sends expression signal out via either 1/4 inch TRS cable or 4 conductor Soundblox compatible 1/8 inch sensor cable OUTPUT 2 sends expression signal out via 1/4 inch TRS cable