Up for sale is an Electro Harmonix Big Muff Pi vintage guitar pedal in well-used condition.  This is the 1st edition, version 3 of the classic Big Muff pedal with no "AC" graphic on top, along with the "ON/OFF" graphic above the tone knob.  Also has the typical V3 "3003" circuit board populated with BC239 transistors.  One of the pots date this pedal to approximately 1977.  Everything is completely original except for the sustain pot and replaced battery clip.  Also missing two screws on top.  More importantly, works perfectly without any issues whatsoever.  This is truly a classic BMP that you do not want to miss.  Check out all the hi-res pictures and ask any questions you might have.  Thanks!