Four mechanically-stable aluminum frames interconnected by corner connectors comprise the "plusline" case system and permit individual determination of the case size by simply selecting the appropriate length. The use of modular frame sections makes possible 19-in. bench cases, electronic cubicles up to 24 height units, PC Big Towers AT-ATX and tailor-made case dimensions. For heavy components, slide rails with variable depth, shelves and intermediate bottoms are available. For increased protection, the case can be fitted with a fully transparent or a solid door. A vase selection of backs walls provides versatility to suit most applications. As an alternative to firmed fixed side walls, detachable walls are available that may be easily removed. In addition, the case systems are offered with adjustable feet or with double rollers, depending on the application and the required degree of flexibility.