Speks Third RockSpeks magnetic balls are the most fun stress relief desk toy around. Keep a set on your desk to be the envy of coworkers or carry 'em in your pocket to break that pesky nail biting habit. Each set is made from 512 2. 5mm rare earth magnets. Speks meet all toy and safety standards and are safe with proper use by anyone over the age of 14. Their magnetic flux index rating is less than 50, however Speks should never be put near or in your nose or mouth.