Features:Delivers that warm， natural tube overdrive sound.By rotating the knobs you can boost the guitar amp for colorful tone or overdrive itself for unique pedal sound.True bypass design， minimizes tone loss and get more control of your pedal.Aluminum alloy housing， good durability.LED indicator shows status of effect and battery condition.The pedal can be powered by 9V battery or AC 9V adapter.3 adjustable knob:Level knob: control the level of the signalTone knob: control the amount of high frequencyDrive knob: adjust the amount of overdriveSpecification:Color: GreenInput impedance: 1M OhmsOutput impedance: 10K OhmsPower: 9V battery or 9V AC adapter (not included)Product size: 11.7 * 6 * 3cm / 4.6 * 2.4 * 1.2inProduct weight: 234g / 8.3ozPackage size: 12.5 * 8.5 * 5.5cm / 4.9 * 3.3 * 2.2inPackage weight: 292g / 10.3ozPackage List:1 * OD-3 effect pedal1 * User manual (English & Chinese)