An exhaust device includes a casing including an inlet configured to receive an exhaust gas, an outlet configured to discharge the exhaust gas, and a chamber disposed therein between the inlet and the outlet. The casing defines a longitudinal axis along its length. The exhaust device further includes an exhaust conduit at least partially received within the chamber of the casing along the longitudinal axis. The exhaust conduit includes an inner surface, an opposing outer surface, a plurality of perforations extending through the exhaust conduit from the inner surface to the outer surface, and at least one protrusion extending outwardly from the outer surface. The exhaust device further includes an absorptive material disposed on the outer surface of the exhaust conduit. The at least one protrusion of the exhaust conduit engages with the absorptive material in order to form an interference fit between the absorptive material and the exhaust conduit.