It's active Treble, Bass ,Gain and Volume controls allow for limitless tone shaping. Added Gain switch for even fatter tones!. The RC Booster Classic offers a super transparent 20db+ clean boost and a +- 15db 2 band active EQ without ever compromising the integrity of the original TONE. It provides a solution to sound degradation, caused by long instrument cables and/or long effect chains between guitar and amp, by strengthening the original signal. True bypass for eliminating any signal interference when switched off. Can be used with AC adaptor (optional) or 9V Battery.