This is a Maxon ST-01 Super Tube Screamer overdrive pedal that I used to own. I haven't used it in a long time, but I've confirmed that it powers on and functions. Compared to a standard Tube Screamer, this one allows for more detailed sound shaping with features like "MID BOOST" and "SOFT/HARD" and "FAT/TIGHT" settings. It can produce sounds ranging from warm crunch to heavily distorted tones. The exterior shows signs of use and minor scratches, but it's in relatively good condition for its age. *The back cover is missing (as shown in the photos). I only used an adapter towards the end, so I used a thin piece of wood and tape as a makeshift back cover. Sometimes the footswitch doesn't respond on the first press. It works if you step on it again lightly, so please be aware of that. This listing is for the pedal only. For those who understand vintage effects, please consider it.