Super Neodymium Disc Magnets, also know as rare earth magnets, are made of neodymium, the most powerful magnet material in the world. They attach to most projects with a super glue-type epoxy, and are ideal for projects that require extreme strength in a small size.Details: 0.315" x 0.118" 10 magnetsWarning: Due to their extreme strength, these magnets are not suitable for children as they can pinch fingers.