Kaca mata, lensa-Iensa, mikroskop, teropong, teleskop, pesawat komunikasi,telephone, airphone, walky talky, handy talky, pesawat telex, segala macam jenis antena,segala macam tipe antena, antena outdoor/luar, antena indoor/dalam, antena parabola, radar, pesawat penerima radio, televisi, tape recorder, video, mesin bicara, gramaphone, rewinder, amplifier, loud speaker, microphone, megaphone, headphone, wireless, VCD, optik, pita-pita magnetik, pita cassette, pita video disk recorder, laser disk, piringan hitam, compact disk (audio, video), booster, accu, baterai, bel listrik, kabel telepon, transformator, travo,ballast, step up, step down, mesin faksimile, komputer, mesin hitung, kalkulator, kas register, printer, pesawat-pesawat ukur, speedometer, ampere meter, meteran listrik, voltameter, modem-modem, monitor (program komputer), CPU, stop kontak, sakelar, switch-switch, fiting-fiting, kombinasi fiting, stecter, sonar, seterika listrik, mesin fotocopy, disket, pesawat-pesawat pemadam api, alat solder listrik