The Grape Phaser provides lush, analog phase shifting courtesy of a simple, two-knob layout. From flowing, liquid tones to fat, funky ones, this simple phaser has a wide range of usable sounds in it. Fantastic for all styles of playing, especially soloing, fretless, and slap. RATE controls the speed of the modulation while COLOR feeds a portion of the signal back through the phase shifting circuit, creating new and super funky bass sounds! *Pedal powered by universal 9-volt power supply only. Not included. 'Rate' controls speed of modulation 'Color" feeds a portion of signal back through the phase circuit, creating new and unique tones Pedal powered by universal 9-volt power supply only. Not included.