CAE WAH MC404 The CAE Wah allows you to switch between two distinctly-voiced Fasel® Inductors with a built-in Boost/Line Driver circuit, internal Q and gain controls, and bright status LEDs on each side of the pedal. This pedal can be powered by a 9-volt battery, a Dunlop ECB003 9-volt adapter, or the DC Brick™, Iso-Brick™, and Mini Iso-Brick™ power supplies (not included).