Combines Pigtronix's Philosopher's Tone compressor with a 2-band EQ and an overdrive/distortion stage in one box — compression for sustain and dynamics, EQ for tone shaping, drive for gain, all usable independently or stacked in either order. Built to cut down how many separate pedals you need on the board. Good condition, includes original box (not pictured) and original Pigtronix power supply.