When silence is a must you can’t go far wrong with these Can silencers. These have been carefully tested and approved for use with most extractor fans. Designed to reduce the noise caused by moving air. Mineral wool insulation minimalizes unwanted fan noise.Can-Filters Silencers – A sturdy Steel construction with dampening qualities to remove or reduce unwanted fan blade noises. The main body of these silencers has a perforated internal surface which allows air noises to be quietened before and after the fan.