The interior of the REM unit is usually lined with chipboard treated with foil in a white or wood pattern (in sanitary units, the interior can be lined with a thin steel sheet).
REM modul je z notranje strani običajno obložen z ivernimi ploščami, obdelanimi s folijo v belem ali lesnem vzorcu (pri sanitarnih moduljih je znotraj modul lahko obložen s tanko jekleno pločevino).