Rare Earth Permanent Round NdFeB Perforated Magnet https://www.mlmagnet.com/product/ndfeb-countersunk-magnet/rare-earth-permanent-round-ndfeb-perforated-magnet.html These are manufactured in a unique way and require special equipment, resulting in higher production costs. This is the material for high-performance magnet assemblies. Due to their extremely high flux density, these magnets are referred to as “super magnets” and can be found in almost every industry. The grade of Rare Earth Permanent Round NdFeB Perforated Magnet is guaranteed, so these magnets meet stringent quality standards.