4 ms·

The FAQ claims they will loose about 1% of their strength every 100 years. http://www.polymagnet.com/faq/ http://www.polymagnet.com/faq/

• hanniabu 11y ago
  Good enough for me...
• schoen 11y ago
  I wonder if that's linear or exponential decay. (It's hard for any user to stick around long enough to notice the difference...)