Guitar distortion effect pedal. The SOLO is the newest member of the Pro Co family of stomp boxes. Although it is housed in the same indestructible and road worthy steel enclosure that has come to be a trademark of Pro Co stomp boxes, the SOLO marks a departure from the RAT series of pedals in more ways than just the new cosmetics. With its enormous range of tones, 3 way selectable "hot, melt, & burn" modes, and highly interactive "scoop" and "tone" controls, the SOLO just might be the most versatile pedal in your arsenal. Even in its highest gain settings, the SOLO remains extremely tube-like, articulate and touch sensitive. Complex chords ring out with clarity, leads sustain with ease. Roll back your volume knob and it cleans up, just like a good tube amp would.The three pairs are accessible via the "hot, melt, burn" slider switch. This has the effect of making the SOLO clip very much like a tube amp going into natural power tube distortion.