Keeley Neutrino Envelope Filter Auto Wah PedalThe Keeley Neutrino gives you all the classic, funk, auto wah sounds and that Jerry In A Box sound. Keeley has used the classic opto coupler design for a rich and warm depth to the effect. Envelope filter sound is an effect triggered by your pick attack or strength. The harder you pick, the harder it wahs! Sounds bubble up from a deep rounded warmth to a shinning brilliance. Solo notes are individually expressive based on how hard you play. The