Material: NdFeB Permanent NdFeB Generator Magnet High precision, High challenge, High quality Neodymium Magnet is a member of the Rare Earth magnet family, and the most permanent magnet in the world. It is composed of Neodymium (ND), Iron (Fe) and Boron (B), which makes them vulnerable to rust if they're exposed to the elements. To protect the magnet from corrosion and to strengthen the brittle magnet material, the magnet is usually coated with nickel. Neodymium Magnet is a member of the Rare Earth magnet family, and the most permanent magnet in the world. It is composed of Neodymium (ND), Iron (Fe) and Boron (B), which makes them vulnerable to rust if they're exposed to the elements. To protect the magnet from corrosion and to strengthen the brittle magnet material, the magnet is usually coated with nickel. Temperature Characteristics: Low grade Neodymium magnet may lose strength if heated above 80° C. High grade Neo magnets have been developed to function at temperatures up to 220° C with little irreversible loss. Grade: N35-N52, 35M-52M, 33H-50H, 33SH-45SH, 30UH-42UH, 30EH-38EH, and 28AH-33AHB. Coating: Ni, Zn, gold, copper, epoxy, chemical, parylene etc. Shape: Arc, segment, disc, cylinder, sphere, block, ring, tile, and ect. Magnetization orientation: Through thickness, axially, radially, multipole, diameter