[ Surveying machines and instruments; ] measuring signaling and checking apparatus and instruments for [ surveying, ] measuring and checking sound waves, sound and audio signals; apparatus and instruments for conducting, switching, transforming, accumulating, regulating or controlling electricity, namely, jacks, plugs, connectors and electrical conduits; apparatus for recording, transmission and reproduction of sound and images, namely, headphones, headsets, microphones, loudspeakers, audio earpieces, stereo sound reproducers, multimedia equipment, portable music players and telephones and mobile telephones; [ blank magnetic data carriers; prerecorded magnetic data carriers featuring sound and music files, ] motion picture films and data and software used for the instrument, signaling, checking, and manipulations of sound waves, sound and audio signals; blank recordable optical discs; calculators; data processors; computers; sound equipment, namely, amplifiers, graphic equalizers and sound cards for computers; software for recording, transmission and reproduction of sound for use in the production and reproduction of music, home and portable audio reproduction and scientific and industrial audio production and reproduction