Speaker Neodymium Magnet, Excellent Demagnetization Resistance Capability Neodymium magnetGrade: N42SHSize: 42-33 x 6mmMaterial: sintered NdFeBCoat: Ni-Cu-Ni excellent resistance of corrosionPassed: ISO9001:2000 and RoHSCustomized specifications are welcomePlease inquire us with your dimensions (diameter x thickness), grade, coat and tolerance requirement