Xotic RC Bass Booster pedal. I took this in as part of a purchase/trade deal here on TB. Excellent condition, with the addition of red knobs to make settings easier to see on stage. Dead simple boost with volume, gain, treble and bass knobs. Makes everything sound better, can do clean boost or add a little grit if you like. 15dB boost / cut function and a very smooth clean boost. Clean Velcro on the back. $75 shipped CONUS.