This very cool collectable was produced in the early 90s and then sadly discontinued only a few years later. You basically have your choice between 2 different tremolo modes and two different panning modes. In each of these two modes you have the abiltiy to select between a square or sine wave. The tremolo sounds fantastic in either mode but the helicopter choppiness of the square wave setting always made us the happiest. The pedal sounds wonderful in mono but throw another amp onstage and you've got pure heaven. Our only complaint is that the usable range of the tremolo's rate was only found in the last 20 percent of the pedal's turn. The lowest rate was practically glacial unless you love super slow swells. The newer Boss TR-2 Tremolo fixed this issue but isn't about time for a new tremolo with some newer and wilder variations?