The BEHRINGER HB01 HELLBABE is a surprisingly versatile wah pedal. Its most significant feature is the elimination of the "physical switch" and "variable resistor (pot)" found in typical wah pedals (like the Cry Baby), instead employing an optical sensor. This results in less crackling (noise) and enhanced durability. Key features include: 1. "Switchless operation" that activates with a step Unlike many wah pedals that require a firm push of the toe to click the switch, the HELLBABE automatically turns ON simply by moving the pedal with your foot. Spring-back mechanism: The pedal returns to its original position (heel side) with a spring, automatically turning OFF. Off-timer adjustment: The time it takes for the effect to turn off after releasing your foot can be adjusted with a screw on the back. 2. Amazing sound shaping capabilities Unusually for this price range, it has a wealth of knobs for detailed sound customization. RANGE: Adjusts the frequency range between 250Hz and 440Hz. Lowering this allows it to be used with bass guitars. Q: Adjusts the sharpness of the filter. Sharper settings emphasize the "wah wah" vocal-like effect. FINE: Adjusts the high-frequency extension, allowing for a brighter sound. BOOST: Allows for a volume boost of up to +15dB. Useful for increasing volume during solos. The unit has some scratches from use, but there are no issues with performance. The boost switch on the side of the unit has come off, and I have been using a stick-like object to press it. Since the boost sounds better, I have been keeping it pressed, but there have been no problems. Thank you.