The Noise Killer provides two different noise reduction modes for you to choose from, dependent on your ideal sound. The modes can be selected easily, via the Mode Switch and they include Hard or Soft. When in Hard mode, this provides a hard and dramatic effect of noise reduction whereas Soft mode offers a soft and gradual noise reduction effect. The Mooer Noise Killer also features a Threshold knob that allows you to adjust the level of the noise reduction, offering wide versatility.