Ring Shape Neodymium magnet for Speakers The lagest size can be Dia 220mm, Typical Grade: ... , Tin, Epoxy, Ni-Ag, Ni-Au, etc. Applications: Wind Power Generators, Motor Parts, MRI/Nuclear Magnetic Resonance (NMR), Magnetic Separators, Cleaning ... be 150mmx150mmx50mm, the smallest can be 2.00mmx1.50mmx0.50mm for the block shape.Machine: Neodymium magnets should be machined by ...