The wah mode on the Morley PWV-II foot pedal features an output-level control, a LED light to let you know when wah mode is on, and a "Clear Tone" buffer circuit to decrease "loading" of the guitar signal. All the wahs, from Hendrix to Vai and beyond. In volume mode, the PWV-II pedal gradually adds gain from off to halfway for steel guitar-like swells, and increases faster from mid to full-on. Famous Morley thick sound and wide bandwidth. Electro-optical design for noise-free operation. Rugged metal construction. Powered by optional Morley adapter or 9V battery.