Tech 21 Killer Blue Wail Bass Wah Pedal

From the listing

Seller's description

The Killer Blue Wail Bass Wah preserves the original tonal integrity of vintage wahs and overcomes familiar shortcomings, such as excessive noise and unreliable mechanical parts. Utilizing light sensor technology, there are no clunky pops, no irritating scratching sounds, and no pots to wear out. Machined from solid billet aluminum, the heavy duty housing will provide long life —on and off the road. Rather than utilizing simple band-pass or low-pass filters, the Killer Wail’s faithful emulation uses a specially-designed filter. It not only changes the frequency, it also changes the Q, which is the sharpness of the filter. Unlike guitar wahs, the Killer Blue Wail for bass keeps the low-end intact. The Killer Blue Wail features a spring-loaded rocker that returns to its resting/bypass position when you remove your foot from the pedal and automatically engages when you press forward on the pedal. SPECS: Measures:  3.375″w x 8.0″l x 1.75″h Weight:  24 oz. Operable with 9V alkaline battery (not included)