Abstract: Reduced-noise devices or their components, in particular engine or combustion units and their components or fluid-carrying systems and their components, which are constructed, partially or wholly, from thermoplastics and which, at a distance from the surfaces of the devices, have at least one perforated plate, which is firmly connected, rests essentially with a form fit on continuously circumferential attachments on the thermoplastic component and encase the devices, in part or completely.