Acoustic couplers; Apparatus for recording, transmission, processing and reproduction of sound, images or data; Communications headsets for use with communication radios, intercom systems, or other communications network transceivers; Computer memories; Electric cables, wires, conductors and connection fittings therefor; Electric wires; Electrical plugs and sockets; Electrical transformers; Galena crystal detectors for use in electronics; Integrated circuits; Telecommunications and data netwo...