Fountain pens and ink cartridges therefor; mechanical pencils and leads therefor; erasers; ball-point pens and refills therefor; felt-tip pens and refills therefor; marking pens and refills therefor; inks and all other writing instruments

Optical isolators, optical switches, optical couplers, optical connectors, optical circulators, polarized beam splitters, non-polarized beam splitters, band pass filters, faraday rotation elements, spherical-ended fibers, oblique-ended fibers, collimated fibers, chip carriers, laser diode receptacles, heat sinks, ferrules, sleeves, laser diode caps, optical amplifier modules, magneto-optical sensors, optical multi-/demulti-plexors, optical wavegides, optical fiber assemblies, spherical lens assemblies, laser diode-module assemblies, optical receiver module assemblies, plug assemblies; electro-acoustic transducers, electric vibrators, electric buzzers