Vintage Maestro Octave Box. Has a great organic, earthy, fat, octave-down sound. Works really well with dirty tones, too. The footswitch may need to be cleaned (or inexpensively replaced) as occasionally you have to click it a few times to engage. (Or perhaps it just needs to be used a bit as it's been sitting unused for years.) Otherwise, the knobs all work fine and the sounds is fine.Hear this actual pedal, played this week, here: http://www.youtube.com/watch?v=SYmi8Dtrq-0Cosmetically it looks as though it has been used, with some scratches, one missing rubber mini-foot, some replaced screws, a non-original but sturdy battery holder, and one hole filled on the back. See photos for details. All said, it feels solid and sturdy.I believe these were made by All-Test Devices for Maestro (a Gibson subsidiary and creators of the Echoplex) from 1971-1975. My guess is this is an earlier model than the only other two I can find right now (they're both on Reverb). They are more blue than aqua in color and are priced at $275 and $399. Buy this one with confidence from a trusted seller. No reserve.