... Shape Neodymium magnet for Speakers The lagest size can be Dia 220mm, Typical Grade:N35,N40,N42,N45,N52,35H,38SH Speaker Neodymium ... Ni-Ag, Ni-Au, etc. Applications: Wind Power Generators, Motor Parts, MRI/Nuclear Magnetic Resonance (NMR), Magnetic Separators, Cleaning Machine ... required: about 25KOeShape Available: blocks, bars, discs, rings, arc segments, etc.Grade Available:N35 to N53,N,M,H ...