Magnetic fields such as those generated by electric motors, loudspeakers, medical equipment and many other everyday sources cause the Nivarox balance spring to become magnetized which adversely affects timekeeping accuracy.
Sinn solves this problem for the models listed on this page by using a protective sheath consisting of a closed, magnetically soft inner case that includes the dial, the movement holding ring and the case back.
These Sinn watches offer extreme protection against magnetic fields, and are rated to 80,000 A/m (also known as 1,000 Gauss or 100 mT).
Standard watches are typically rated to 4,800 A/m.
We've prepared an extensive article about mechanical watches and magnetism which you may read at this link