A silencer, comprising: a housing; and a silencer insert for a silencer of an exhaust system, the silencer insert being received by said housing, the silencer insert comprising: a first partition wall defining a first plane; a second partition wall defining a second plane different from the first plane; a connecting wall defining a third plane different from both, the first plane and the second plane, and being arranged between the first partition wall and the second partition wall; wherein at least one of the first partition wall, the second partition wall, and the connecting wall comprises at least one perforated area; wherein the connecting wall is formed in one piece with both, the first partition wall and the second partition wall; and wherein the first plane encloses with the second plane an angle of not more than 60° or not more than 45° or not more than 30°, or wherein the first plane and the second plane are in parallel; characterized in that at least one of the first partition wall, the second partition wall, and the connecting wall comprises a coupling portion at the part of its perimeter not connected to another wall (11, 12, 13), where the coupling portion of the respective wall (11, 12, 13) includes at least one of a protrusion and recession along its circumferential direction configured for engaging a further coupling portion of the housing of a silencer, wherein at least one further coupling portion having the shape of a bead or of a protrusion is formed into the housing, and wherein the further coupling portion of the housing engages the coupling portion of the silencer insert. a housing; and a silencer insert for a silencer of an exhaust system, the silencer insert being received by said housing, the silencer insert comprising: a first partition wall defining a first plane; a second partition wall defining a second plane different from the first plane; a connecting wall defining a third plane different from both, the first plane and the second plane, and being arranged between the first partition wall and the second partition wall; wherein at least one of the first partition wall, the second partition wall, and the connecting wall comprises at least one perforated area; wherein the connecting wall is formed in one piece with both, the first partition wall and the second partition wall; and wherein the first plane encloses with the second plane an angle of not more than 60° or not more than 45° or not more than 30°, or wherein the first plane and the second plane are in parallel; characterized in that at least one of the first partition wall, the second partition wall, and the connecting wall comprises a coupling portion at the part of its perimeter not connected to another wall (11, 12, 13), where the coupling portion of the respective wall (11, 12, 13) includes at least one of a protrusion and recession along its circumferential direction configured for engaging a further coupling portion of the housing of a silencer, a first partition wall defining a first plane; a second partition wall defining a second plane different from the first plane; a connecting wall defining a third plane different from both, the first plane and the second plane, and being arranged between the first partition wall and the second partition wall; wherein at least one of the first partition wall, the second partition wall, and the connecting wall comprises at least one perforated area; wherein the connecting wall is formed in one piece with both, the first partition wall and the second partition wall; and wherein the first plane encloses with the second plane an angle of not more than 60° or not more than 45° or not more than 30°, or wherein the first plane and the second plane are in parallel; characterized in that at least one of the first partition wall, the second partition wall, and the connecting wall comprises a coupling portion at the part of its perimeter not connected to another wall (11, 12, 13), where the coupling portion of the respective wall (11, 12, 13) includes at least one of a protrusion and recession along its circumferential direction configured for engaging a further coupling portion of the housing of a silencer, wherein at least one further coupling portion having the shape of a bead or of a protrusion is formed into the housing, and wherein the further coupling portion of the housing engages the coupling portion of the silencer insert.