The driving guitar force behind Creed and Alter Bridge helped design the Morley Mark Tremonti Wah - the most advanced, hottest wah around. No switch, just step on it to engage the wah and step off to disengage. Boost knob adds 20dB of wah boost and the tone is a perfect hybrid of classic and contemporary wah voices. Electro-optical design means there are no pots to wear out. Clear-Tone buffer circuit, diamond plate footpad, and LED indicator. Works great with bass guitar. This pedal can be powered with a 9-volt battery or plug 9-volt adapter. Includes 2-year warranty.