cases and casing systems for electronic and electromechanical apparatus and instruments; namely, shell-type cases, wall-mounting cases, flat-pack cases, modular cases, cases shaped like a desk, plug cases, keyboard housings, hand-held boxes, pocket-size cases, desk-top cases and parts thereof, all being shielded against high frequencies; cabinets for apparatus and racks for the installation of electronic and electromechanical apparatus and parts thereof; accessories for the aforesaid goods; namely, battery clamping and holding devices, battery contacts, parts to seal a case against unauthorized opening, parts to fasten cases or boxes to walls, screw joints, parts to mount apparatus or instruments within cases, screw joints for cables, parts to serve as feet for cases to prevent movement thereof, gripping and carrying handles, parts serving as hinges, joints, grips, clamps; control knobs and slides for electronic and electromechanical components of all kinds and parts thereof