From Cast Engineering:The Pulse Drive is our enhanced version of the classic Anthony Leo tremolo circuit. You can get those warm, clean tremolo tones to swampy vibes to choppy goodness. Having 30db of boost on board, you can add some extra grit to the tremolo or turn the depth off and have straight boost/drive to send your amp into sweet overdrive land! Visually this pedal stands out with our light up knobs that blink with the rate of the tremolo Specs: Bypass Switch - true bypass of signal Rate - adjusts tremolo speed Depth - adjusts intensity of tremolo Level - adjusts volume/acts as boost after unity gain Turn depth all the way down to use as just a boost Light up knobs blink to tremolo rate 9V Battery or standard negative tip power supply LIFETIME WARRANTY Top Quality Components Designed and Hand Built in Atlanta, GA