Long magnetism on magnet
The magnetism possessed by a magnet can actually be called a permanent magnet. It has a very high coercivity and its own magnetic force is quite stable when it is working. Even if the natural environment and magnetic field conditions are different, it usually does not show demagnetization and magnetic changes. And if the environment in which it is used is very stable, the magnetism possessed by the magnet itself can be used for a long time, and it will not be very lossy.