The potentiometer has a 25k ohm resistance suitable for the audio path of active instruments or buffered effect returns. Use the A input / A output for the left channel and the B input / B output for the right channel. For use as a mono volume pedal, use the A input and A output. For use with stereo cable installations using TRS type stereo plugs use the B input and B output. Overall Volume Pedal dimensions: 4" W x 11" L x 2 3/4" H.