Boss XS-1 Poly Shifter Pitch Shift Effect PedalWhen it comes to pitch shifting, you're not likely to get an experience more streamlined than the Boss XS 1 Poly Shifter. Driven by magical Boss algorithms years in the making, the XS 1 Poly Shifter transforms the overall pitch of your instrument with speedy tracking, crystal clear response, and zero compromise in tone. Shift down, simulate a capo, land extreme octave jumps, whatever you feel with the XS 1. The Boss XS 1 Poly Shifter features class