Electro-Harmonix Micro Metal Muff Distortion Pedal Volume, tone, and distortion knobsTop boost switchEffect on/off footswitch with red LED indicator 15db boost and cut around a carefully selected mid frequency guarantees huge scoop possibilities Selectable top boost ranges 9V DC power jack, small and compact so it won't take up valuable space on your pedal board The Micro Metal Muff provides an awesome array of alloys ranging from slithering mercury to molten slag, lead belly to blast furnace dross