Introducing the Green Crystal Overdrive, the product of years of research. Giving you a clear, transparent, warm and dynamic overdrive tone like a tube amplifier. With the high and low frequency controls you can dial in your ideal EQ. Get the exact amount of overdrive you want by adjusting the drive and output controls. The three way switch gives you three different options for diode clipping, giving you even more tonal control. True Bypass design preserves your tone when the pedal isn't in use.