Boss NS-2 Noise SuppressorThe NS 2 Noise Suppressor eliminates unwanted noise and hum without altering an instrument's natural tone. It's the perfect pedal to quiet down any pedalboard or effects setup. Compact noise suppression pedal for eliminating noise and hum in guitar and bass effects and amplifier setups Unique noise detection circuit preserves the natural attack and envelope of an instrument's sound Threshold and Decay knobs allow for shaping the elimination