Electro Harmonix - Tone Corset Analog CompressorThe Tone Corset, our 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!" 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 know adjusts how quickly the compressor