Apparatus for recording, transmission and reproduction of sound images; scientific, digital, electronic, electrical apparatus and instruments for weighing, namely, scales and balances; scientific, digital, electronic, electrical apparatus and instruments for measuring, namely, derived-unit measuring machines and apparatus, instruments for measuring length, bevels, digitizers, measuring rules; scientific, digital, electronic, electric apparatus and instruments for checking, namely, graduation checkers, apparatus for checking flight parameters; electrical energy utilization metering devices; apparatus and instruments for digital data transmission via an electrical distribution network, namely, cables for electrical signal transmission, apparatus for transmission of communication, digital data transmitters; apparatus and instruments for conducting, distributing, transforming, measuring, accumulating, setting, supervising and controlling electricity and electrical consumption, namely, fibers for conducting electrical charges, electrical conductors, conductivity meters, electrical relays and transformers, electrical distribution boxes and consoles, automatic electrical distribution apparatus, electric accumulators, electrical controllers; electrical and electronic apparatus, instruments and components, namely, potentiometers, voltage regulators, capacitors, diodes, transistors, electrical source selectors, electrical and piezoelectric switches, diffraction light valves for use in electronic displays, transformers, electrical transmitters, fuses, electrical plugs, electrical sockets, electrical connectors, frequency meters, batteries, battery chargers, plug adaptors, antennas, plug-in connectors, and electrical connection boxes, electrical wires, timers, telephones in the nature of interphones, power supplies, electronic calculators, electronic voltage testers, metal detectors; electrical and electronic circuits, namely, circuits for heavy current, decision circuits, electronic circuits for error correction, electronic integrated circuits, integrated circuits; computers and computer peripherals; computer software for use in controlling and setting electricity consumption; microprocessors, microcontrollers; telecommunication apparatus, namely, telephones, answering machines, telecopiers, electronic device for transmitting data over telephone lines, modems, mobile phones and telephone cables