I have an as-new MXR Bass Auto-Q envelope filter/lo freq oscillator. No marks or scratches, works as new. I may even have the original papers around here somewhere. Bass Player did a review of this pedal and gave it high marks. Unlike a lot of envelope filters, you really can't get a bad setting out of this unit. The controls are very easy to understand--it's an envelope filter first, then you can blend in an oscillator as the note decays. I take paypal, have lots of references, and am an Ebay power seller--in this case, as in almost all others, I am only asking what I've got in it. $80 shipped to your lower 48 door.