

Each output gives the same pitch and rate controllable oscillation, however, each one can also be filtered with the knob just above the output. And, there's a master filter/volume knob, too. Runs on a 9v positive tipped adapter.
Of course, not being one to let a perfectly good electronic instrument just sit there innocently being what it should be, I added more knobs and switches that make it squeak and grind. I don't suggest using this for it's original, medical intentions anymore. I think it was meant to control muscle contractions. If you used it now, your muscles might balloon up until you look like a freakish hulk. Like one of those guys that looks like a pile of grapes.