Egevent EYSA-EDSA series circular duct type mufflers are used to prevent sound transmission between ducts and rooms, and to reduce the sound intensity caused by the friction of air moving elements and air. The outer body is made of galvanized sheet material, the inner surface is perforated and the glass wool or rock wool material is used between the two surfaces. Standard muffler length: 450-950-1450 and 1950mm according to the connection diameter. RSA-2 series is used in diameters of ø400 and above and there is a rectangular perforated sheet metal section in the bottle of this series and this section is used for insulation. covered with material.