TWA WR-03 Wah Rocker Guitar Filter Effect Pedal Range Control - allows the user to adjust the overall frequency band in which the filter is sweeping. This allows for fine-tuning of the filter sweep without adjusting your playing dynamics. Gain Control - adjust the output level of the pedal from unity gain to a healthy boost. The original WR-3 could get lost in a dense mix-well, not anymore! Blend Control - Our version features a continuously variable Blend control rather than a Blend switch, allowing for a much beefier bottom-end and a wider variety of tones. Guitar/Bass Switch - an Added bonus, we built the sounds of the almost-as-legendary Bottom Wah Rocker into our pedal! Get that super-fat, low-end swamp enjoyed by Juan Alderete & Justin Chancellor.