The 535Q is the Swiss Army knife of wah pedals. It provides control over the most important wah parameters, making it easy for you to create your ultimate wah tone. Select the frequency center of the effect, then dial in the frequency range to be swept by the pedal. From narrow and sharp to broad and subtle, this amazing wah can deliver it. Once you've got your sound, make sure it gets heard with the adjustable, switchable boost that can create endless sustain on any note. Power: Dunlop ECB003 AC Adapter or Single 9 volt battery