The EOV Optical Volume pedal from Morley uses an electro-optical circuit instead of traditional pots, which can become scratchy or wear out over time. The EOV"s smooth optical taper is great for volume control or for creating lush, violin-like swells. Built to last with a cold-rolled steel housing, easy-access battery compartment, and LED on/off indicator. Uses 9V battery or Morley 9V regulated adapter (sold separately).Electro-optical volume circuit eliminates mechanical pots Smooth taper for volume control or dramatic swells Cold-rolled steel housing Easy-access battery compartment LED on/off indicator Powered by 9V battery or Morley 9V regulated adapter