Features:Built-in operation amplifier with low noise, natural and clear 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 a battery or AC 9V adapter.3 adjustable knobs:Depth knob: control depth of effect soundVolume knob: control volume of effect signalSpeed knob: control speed of chorus effectSpecificationsInput Impedance: 100 kohmOutput Impedance: 150 ohm on max VolumeRecommended Load Impedance: 10 kohmEquival Input Noise: -90 dBu or lessCurrent Draw: 5.5 mA (DC 9V)Power: 9V Battery or 9V AC Adapter (not included)Product size: 11.5 * 6.6 * 4.7cm / 4.5 * 2.6 * 1.9inProduct weight: 237g / 8.4ozPackage size: 14.5 * 9.3 * 7.1cm / 5.7 * 3.6 * 2.8inPackage weight: 284g / 10ozNote:Please use the 9V power adapter whose polarity is positive pole outside and negative pole inside. Otherwise, the product may not work properly.Package List:1 * ACH-1 Chorus Pedal1 * User manual (English & Chinese)