Electro-Harmonix Nano Q-Tron Envelope Filter Effects Pedal SilverThe Electro Harmonix Nano Q Tron envelope filter effects pedal is a versatile effects modulator thats suited to a wide range of genres and instruments. The Nano Q Tron responds to the users playing style and dynamics, with the input signals volume controlling the cutoff or center frequency of a swept filter. The results are tone altering effects ranging from subtle to dynamic, auto wah to ultra funkyall inspired by how you play and highly interactive.