Ring Shape Perforated Ferrite Permanent Magnet
https://www.mlmagnet.com/product/ferrite-ring-shape-magnets/ring-perforated-ferrite-permanent-magnet.html
Ring perforated ferrite permanent magnet is a kind of high magnetic force of the permanent magnet with a molding method of high-temperature sintering and perforation, which has good processing property and heat resistance, small external magnetic flux density, strong demagnetization resistance, easy to process. It has wide applications in motors, generators, speakers, and other equipment.