Wampler Ego Compressor, Effect Pedal for Electric Guitar, The Blend knob allows you to mix in the unprocessed signal to take a full advantage of the compressor, meanwhile it offers dynamic attack, Controllers: Volume - Sustain - Attack - Tone - Blend, LED: Effect On / Off, Foot switch: Effect bypass, Connections: (6.3 mm jack), output (6.3 mm jack), power supply connection (coaxial socket 5.5 x 2.1 mm - negative pole inside), Power consumption: 14 MA (+9 V) / 22 mA -18 V), Powered by a 9V battery or a 9-18V DC power adapter (not included), Suitable optional power supply: Article Nr #409939#, True Bypass, Dimensions: (W x D x H) 89 x 114 x 38 mm, Made in USA