This makes for a more rich overall phasing effect. You can precisely sync these effects by tapping the pedal to the desired tempo. The Rate, Depth and Tone knobs allow you to dictate the kind of phasing sound you want. With the inclusion of the optional Roland EV-5 expression pedal, you can control the rate and depth of the phasing as you play. There are also preset multi-stage phases with selectable stages, so that you have a wide range of frequency and rate. The Boss PH-3 Phase Shifter comes with a five year warranty.