In the words of JHS Pedals:The JHS Pedals 3 Series Overdrive offers a wide range of overdrive sounds within straightforward design aesthetics. You can achieve anything from boost, transparent low gain, to huge amp-like medium overdrive sounds. The simple knob functions give you control over the Volume, Body (or EQ), and Drive. The Gain toggle gives you a choice between more saturated and compressed or more open and crunchy dynamics.This switch plays a big part in how the pedal responds to your playing and touch as a player.