COSM modeling gives you the sound of 16 classic overdrive/distortion pedals plus 6 all-new tones, while deep-level controls let you shape your own sounds. Attack Shape and Heavy Octave knobs let you profoundly impact the effect. 4 user memories and line out with amp simulator that's also a headphone out. Amp control jack lets the OD-20 double as a footswitch for switching amp channels. BOSS 5-year warranty.
Features:

• 16 classic overdrive models
• 6 brand new models
• 4 user memories
• Attack shape and heavy octave knobs for deep-level control
• Headphone out/line out with amp simulator
• Works as a footswitch for changing amp channels