The Walrus Audio Fathom reverb pedal features four unique reverb algorithms (hall, plate, lo-fi, sonar) and three levels of modulation. Controls include a Dampen knob to suppress high frequencies, X knob to adjust algorithm-specific parameters (Pre-delay and octave up/down mix), smart bypass switching, Sustain switch to momentarily increase the reverb time to near infinite, wet/dry mix knob and time adjustment.