This pedal is unique in that it is both a wah and a volume pedal, saving space on your board. The pedal also has a 20 db boost. Below is the L&M description. The Power Wah Volume is the ultimate space-saving combo pedal. You get the classic Morley Power Wah with it's vintage tone, wide sweep and 20 db clean boost and a smooth audio volume taper. Pedalboards rejoice! Features • Switchable combination Optical Wah and Volume Pedal. • Boost knob allows up to 20 db of clean boost in Wah mode. • Smooth Audio Volume Taper. • New 20/20 Buffer circuit that prevents signal loss and maintains tone. • Silent switching to prevent pops and noise. • Powered by one 9-volt battery or optional Morley 9V adapter. Compatible with most 9V adapters. • MQ2 custom Inductor, LED indication, cold-rolled steel housing, quick clip battery door, glow-in-the-dark treadle grip/toe-end logo. Specifications Power: 9V Battery or 9VDC 300mA regulated (center negative) Indicator (right): Wah Mode LED on, Volume Mode LED off Dimensions: 6.75" x 4.5" x 2.75" Current Draw: 6 mA @ 9VDC Weight: 2 lb./ 0.92 kg