Magnet models are typically categorized by their material composition, which is the primary factor determining their overall performance characteristics. The main permanent magnet families include Neodymium Iron Boron (NdFeB), Ferrite (Ceramic), Samarium Cobalt (SmCo), and Alnico . NdFeB magnets are the most powerful and are commonly classified by performance grades such as N, M, H, SH, UH, and EH. These letters and numbers indicate the material's maximum energy product and its resistance to demagnetization (coercivity), with higher grades offering better performance . Manufacturers also assign specific product codes to their offerings. These codes can denote the magnet's shape (e.g., disc, block, ring), dimensions, and any additional features like holders or coatings . For example, a model like "HXH8" refers to a specific magnet holder assembly with defined outer diameter and temperature resistance .