This palm-sized workhorse is incredibly simple to use, with just one knob that sets the threshold where its noise reduction activates. You can set the knob so that the LED occasionally flashes as you play, or stays on continuously for especially severe line noise. It offers up to 20dB of noise reduction to squelch noise created by single-coil pickups, long cords, high-gain distortion pedals, lighting fixtures, and dimmers.