Custom EQ circuitry which allows for total tonal resolution, creativity and control in the low bass frequencies. Also features the innovative Q control which allows the player to select the exact wah tone desired and an adjustable volume control which enables level of Wah to be from almost silent to almost whatever! Stepping on the pedal engages the effect in the lower register creating a smooth transition into the Wah effect. When you remove your foot, silent auto-off switching automatically bypasses the effect. Buffered bypass. Powered by 9 volt battery or AC adaptor (ECB003).