Electro-Harmonix Tone Corset Analog Compressor Effect PedalThe Tone Corset, our new four knob analog compressor, squeezes your guitar tone in all the right ways! Mike Matthews says, "The Tone Corset is the funkiest analog compressor I ever heard on guitar!" Quick Specs Four knob design provides excellent control and gives the user the ability to precisely shape their instruments dynamics. The Sustain knob controls the amount of compression applied to the guitar signal. The Attack knob adjusts how quickly the