MXR Dyna Comp (M-102)The Dyna Comp is a compressor that letsyou set a maximum output level and thesensitivity at whichit kicks in. Thisdevice can produce that percussive, clickysound on a clean guitar that you've heardon so many pop hits. It can also even outthe volume of sustained tones for mellowlead work,Power:Single 9 volt battery or Dunlop ECB-003 ACadapterControls:Footswitch toggles effect on/bypass (redLED indicates on) Output knob setscompressed (attenuated)output levelSensitivity knob sets compression ratio(highest sensitivity is maximumcompression)