Neodymium Rings
Ring or donut shaped magnets are either in disc or cylinder shape but have one or more holes in the middle. They are not as strong as regular disc or cylindrical magnets due to the loss of volume in the hole section.
Ring magnets are commonly used for craft projects, arts, and science experiments which demonstrate magnetic repulsion and attraction. As ring magnets have a hole in the center, it makes it easier to attach or tie string around. Parents and teachers use ring magnets to tie up at the end of a toy fishing rod and glue another thin ring or disc magnet on the back of rubber ducks for children to play with. These ring magnets can also be used as hidden magnetic lids or caps on bottles, like in the lid of a bottle of Chanel perfume.