Brand new, never used Electro-Harmonix Op-Amp Big Muff Pi . This isn't just any fuzz; it’s a faithful reissue of the legendary late-70s circuit that defined the massive "wall of sound" on The Smashing Pumpkins’  Siamese Dream.
Why this pedal is iconic:

• That Sound: Unlike standard Muffs, this uses op-amps for a more aggressive, crunchier distortion with a unique grit that cuts through any mix. 
• Tone Bypass: Features a dedicated switch to bypass the tone circuit, giving you a massive boost in output and a raw, direct signal. 
• Built to Last: Housed in a compact, rugged die-cast chassis that’s pedalboard-friendly. 
• True Bypass: Keeps your signal pristine when the pedal is off.

If you want heavy rhythm playing or intense, singing leads, there is simply nothing cooler than a  Big Muff . This one is literally fresh out of the box—zero miles on it. 
Price: $85 New retail is typically around $96–$101