85183000Microphones and stands therefor; loudspeakers, whether mounted in their enclosures; headphones and earphones, whether or not coupled with a microphone, and sets consisting of a microphone and a number of loudspeakers; audiofrequency electric amplifiers; electrical seem amplifier set headphones and earphones, if coupled with a microphone, and sets consisting of https://jasperfhxlj.smblogsites.com/30610835/the-basic-principles-of-technology-and-gadgets-examples