MXR M291 Dyna Comp Mini Compressor Electric Guitar Effect Effects PedalWelcome, you are looking at a great piece. This is the MXR M291 Dyna Comp Mini Compressor. The Dyna Comp Compressor is famous for its first rate, no nonsense approach to tightening up your guitar signal and creating rich, full bodied sustain. This has been a part of thousands of legendary guitar tones from the 70's into today. The M291 provides those same famous MXR Comp tones in a smaller pedal. This pedal has a simple two knob 1 button layout very