Composition - Neodymium magnets are composed of neodymium (Nd), iron (Fe), and boron (B). The combination of these elements results in a crystalline structure that contributes to the high magnetic properties. However, this crystalline structure also makes the magnets less hard than other carbon steels. Feature - Various sizes can satisfy your various choices. We provide the perfect size for a variety of applications. These magnets have a triple layer coated with Nickel+Copper+Nickel to provide shiny and durable protection. Applications - These magnets are used for educational, research, professional, commercial, or industrial purposes that are sold or distributed to school educators, researchers, professionals, or commercial or industrial users. Tips- Magnets can attract to each other with great force, so avoid dropping them or subjecting them to impacts. Service - Search for Realth on Amazon for more sizes, shapes, functions, and other unique magnets. Our products are designed based on actual demands and needs and are made under ISO 9001 Quality Systems. Please contact Amazon customer service for the after-sale service. Features: - Made from Neodymium permanent rare earth. - Triple layer coated with Nickel+Copper+Nickel provide a shiny and durable protection. - All the magnets are magnetized axially. - All the magnets have maximal operation temperature of 80℃. - Multiple sizes,shape and function satisfy your various choices. - Professional design based on actual demands and needs.