Thank you for viewing. This is a Seymour Duncan STC-3M4. I am selling it because I no longer have many opportunities to use an active bass. 3-band active preamp for Music Man basses. It consists of a master volume, mid, and treble/bass (2-axis, dual-pot). By pulling the volume knob, you can easily get the perfect tone for slap playing. (The PULL position turns on a preset of bass boost and mid cut using a semi-fixed resistor.) It was working without any problems until it was removed. I am selling it at a bargain price because I cannot confirm its operation at this time. I am selling it as junk, so please refrain from returns or claims.