[Booster Pedal] Create the rich distortion sound,make it more powerful. 20db+ clean boost with +/- 15db 2 band EQ, nice embellishing of original tone [Treble Knob]Adjust the intermediate the high frequency to make sound more penetrating, increase the booster. Bass Knob:Adjust the bass. [Gain Knob]Adjust the degree of distortion, clockwise turning increase the degree of distortion with maintaining the guitar notes. [True bypass] Provide transparent tone, LED indicator shows the working state [Solid construction]Durable metal case, mini size suit perfectly for your pedal board. True bypass provide transparent tone, LED indicator shows the working state. High quality guranteed, DC 9V Adapter power supply(not included). Colour: black Material: zinc alloy Size: 95 x 52 x 38mm Package Contents: 1 x Guitar Effect Pedal Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.