The EarthQuaker Devices Erupter Ultimate Fuzz Tone pedal is a fuzz pedal designed unike any other. A pedel two years in the making; Earthquaker's team of wizards painstakingly dug into creating the most well rounded fuzz tone possible. Balanced highs as well as full lows (without muddiness), simpliticy, ease of use and of course super tasty classic fuzz tone became the ingredients of the Erupter. It's one know control gives the users compelte contol over the pedal's bias. When clicked into the middle, you get the best of both worlds; even bias for smooth and clear fuzz. When turned counter clockwise, the tone becomes more spongy with plenty of sag. When turned clockwise, the sound becomes stiffer and more complex. Tighter sound, more output and increased sustain are all symptoms of having the bad boy cranked to the right. All EarthQuaker Devices pedals are hand built by passionate techs in sunny Akron, Ohio.