Dual-mode design offers two distinct wah sounds in a single pedal * Wah One is classic VOX; with that decidedly sweet UK tone * Wah Two provides Joe Satriani"s original drive and voice controls, delivering a wide range of sound-creation possibilities * Battery life: approximately 90 hours (when using zinc-carbon battery) * Power Supply: 9V battery(6F22, 6LF22/6LR61) or AC adapter(sold separately)