Connecting elements for communication networks and data networks, specifically terminal strips, isolating plug connectors and connecting blocks provided with electric contacts, receptacle outlets; leads for cables and cable clamps, connecting cables and connecting cords, single mode and multi mode signal transmission optical fibers, copper plugs,optical fiber plugs, connectors, printed circuit board connectors, optical fiber couplings,protection modules with surge arresters, shield clamps, connecting frames, contoured-section frames and housings for the fiber couplings, protection modules with surge arresters, shield clamps, connecting frames, contoured- section frames and housings for the above-named connecting elements, in particular for use in principal and secondary distribution systems,cable distribution cabinets, branch points and terminal heads; drawer units for housings; optical and electronic connectors, splicers, splice trays, fiber patch cords used to make an optical or electronic connection with optical or electronic plugs and cables with light wave or electrical transmission; modems