Check the listing for details. MXR M291 Dyna Comp Mini Compressor Electric Guitar Effect Effects Pedal. Condition: New, Made in United States. Listed at 115.99 USD. 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 intuitive. With these controls you everything you need to create classic MXR comp tones, owing largely to the CA3080 chip, the same chip used in the original pedals. If you're looking for the sound on countless record, used by legions of performing guitarists, the MXR Dyna Comp Compressor is the answer.