Electro-Optical circuitry and audio taper allow smooth, studio quiet volume control. Minimum Volume knob is used for a smooth transition between rhythm and lead volumes. Minimum Volume control is now foot-switchable. Powers from one 9V battery or optional Morley adapter. LED Indication, cold-rolled steel housing, quick clip battery door and two-year warranty. Features include: · Electro-Optical Volume pedal is consistent and quiet (no pots to wear out) · Audio taper allows smooth volume control or violin type swells · Switchable Minimum Volume Control - use as either a Rhythm/Lead pedals or Volume pedal with the click of a switch · Minimum Volume knob is used for a smooth transition between rhythm and lead volumes · Powers from one 9-volt battery or optional Morley 9V adapter · Cold-rolled steel housing, LED indication, quick clip battery door and two-year warranty · Works with guitar, bass or keys