Artec SE-OE3, Acoustic Outboard EQ - preamp and 3-band EQ for acoustic guitar. Controls for treble, middle, bass and volume, true-bypass, powered by 1x 9V battery (not included - optional 132579) or power supply (not included - optional 108096), heavy-metal enclosure, dimensions: 75.5 x 116 x 49mm (WxDxH)