Amazon.com: BOSS VE-2 Vocal Echo Pedal for Singing Guitarists | Real-Time Vocal Harmonies and Effects | Create Harmonies with Manual Key Selection | Connect Guitar for Auto Harmony Function | 24 Harmony
Guitar Pedal X - GPX Blog - 9 of the Best Compact and Medium Format Schumann PLL Style Harmonizer Fuzz Pedals
Top 9 Pitch-Shifting & Harmonizer Pedals For Guitar & Bass – My New Microphone