Apparatus for transmission of communication; Cases for pocket calculators; Cell phone straps; Computer keyboards; Computers; Converters; Galvanic cells; Headphones; Loudspeakers; Microphones; Protective films adapted for computer screens; Protective films adapted for smartphones; Sound recording apparatus; Transmitters of electronic signals; Vibration meters; Videorecorders; Car videorecorders; Carrying cases specially adapted for pocket calculators and cellphones; Electrotechnical vibration ...