Ok there is an issue with this pedal. The depth knob does work. It looks like the pot has either been replaced or just gone bad. It turns on and work just without the depth knob in the circuit so you just get volume with depth on full blast since the pedal isn’t getting any resistance from the depth pot. I was planning on getting it fixed eventually but I don’t have the time right now. Other than that it’s a silicon version the most popular of the circuits that were made aside from the germanium ones. I had bought it off the OfferUp listing months ago from an ex guitar center employee who had it in his collection and he had it up for $300. Pretty cheap for what they go for on reverb, only asking $250 so someone else can fix it and resell it if they want.