Guitar mono volume pedal, equipped with a jack socket for input and one for output. The pedal-guitar-amplifier connection is made through two cables that link the pedal input to the guitar output or any other instrument with mono output and the pedal output to the amplifier's input.
The VM12 is an in line volume / swell pedal for guitars. Used between the guitar and the amplifier this provides additional volume control for the guitar output level. It can be used to create the "violin swell" effect