TDK is the parent company of a group engaged in the manufacturing and sale of electronic components, electronic devices, recording devices, semiconductor devices, and recording media and systems. Co.'s primary products include ferrite cores, ferrite/metal/rubber/plastic magnets, ferrite/metal electrodes, and ceramic capacitors; optical isolators, inductors/coils, transformers, noise filters, power supplies, and converters; magnetic heads for HDD and thermal printing heads; ICs for LAN-use and modems, organic EL displays, solar cells, and factory automation systems; and audio tapes, video tapes, floppy disks, CD-ROMs, MDs, DVDs, BS/CS antennas, software, and network adaptors.