The EF102 Photo Thermin V.2 packs the unique tone of a theremin into a compact and modern form. The pitch of the theremin can be varied using the optical sensor installed on the main unit. By adding delay and reverb, you can create even more fantastic sounds. The EF102's optical sensor uses a highly sensitive one. The pitch changes depending on the amount of light hitting the sensor, so it may take a little practice at first to output sound while keeping the pitch fixed. However, this high sensitivity allows you to move the main unit left and right, or shake it, to raise and lower the pitch or create a vibrato-like effect. A toggle switch switches between triangle/square waveforms. Powered by a DC9V center-negative adapter. It does not run on batteries. A rare instrument that you rarely see for sale! Personally, I would like noise artists and shoegaze musicians to play it aggressively and experimentally.