If your ventilation system is too loud you can use these flexible fan silencers to reduce the noise coming from it. These silencers are flexible which allows them to fit neatly into a position you place them in. They are connected into the system on the outlet side of an inline fan, thus reducing the noise produced by the fan. The insulation is able to absorb any noise made by the fan due to the perforated inner metal sheet. You will find that these silencers are very easy to connect with the simple use of either duct tape or a duct clamp. All of the sizes are of 1m long and are made of a high quality aluminium.