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. Due to their extreme strength, these magnets are not suitable for children as they can pinch fingers. MN07045 disks measure .315" dia. x .118" thk. and are available in packs of ten. MN07046 disks measure .472" dia. x .118" thk. and are available in packs of six.