Hi Hobbit, thanks for the link, I read through and here are some of the question
1) the watch with 4,800A/M can withstand these Electric motors, loudspeakers or door closers' magnet? or greater is needed like 80,000A/M?
2) Or the other way to look at it like 4,800A/M can only withstand those freezer magnet and not those big magnet like the one use in the car speaker. I am not sure