The Boss CE-20 Chorus Ensemble Twin Pedal is one of the best chorus effects pedals made. Lush but transparent. Models classics such as the CE-1 and SDD-320 and lets you create entirely new effects including chorus for bass and acoustic guitars. Brilliance and Ambience knobs provide unprecedented control over the effect engine. 6 chorus modes, 4 user memories with pedal recall, stereo I/O, headphone jack, and BOSS 5-year warranty.