Casing computer, pesawat penerima radio, televisi, tape recorder, video, VCD,DVD, mesin bicara, gramaphone, pickup, rewinder, amplifier, loud speaker, speaker mobil, microphone, megaphone, headphone, wirelles, optik, kacamata, lensa-lensa, mikroskop, teropong, teleskop, pesawat komunikasi, telephone, airphone, walky talky, handy talky, pesawat telex, pita-pita magnetik, pita cassette, pita video disk recorder, laser disk, piringan hitam, compact disk(audio,video), antena, booster, radar, parabola, accu, baterai, bel listrik, kabel telepon, transformator, travo, ballast, stepup, stepdown, mesin faksimili, komputer, mesin hitung, kalkulator, kas register, mesin teleks, printer, pesawat-pesawat ukur, speedometer, ampere meter, meteran listrik, volta meter, modem-modem, monitor(program komputer),cpu, stop kontak, sakelar, switch-switch,fiting-fiting, kombinasi fiting, stecker,sonar, seterika listrik, mesin fotocopy,disket, pesawat-pesawat pemadam api, alat solder listrik