https://www.tymagnetics.com/products/block-ceramic-magnet-c8-6x4x1-inch.html Block Ceramic Magnet C8 6X4X1 inch Ferrite magnets, also known as ceramic bar magnets, are made from a mixture of iron oxide and other materials such as strontium or barium. They are known for their low cost, high magnetic resistance, and good temperature stability.