In the words of Walrus Audio:

A tone tweakers delight, the EB-10 works as a preamp, EQ and boost with three available presets to meticulously craft your guitar’s sound allowing for studio-grade electric guitar tone in a live setting. Each rotary knob offers up to 12dB of boost OR cut of Low, Mid, and High frequencies, based on where you have the toggle switches set. When the Boost switch is engaged, add a 10dB MOSFET boost for some great extra punch.