... Various shape 3.Stable performance 4.Good corrosion resistance Ring magnets for speaker material: sintered NdFeB magnet;rare earth permanent magnetsshape: ... N35SH-45SH, and N28EH-N33EH for NdFeB (Neodymium magnet), and Y25, Y30, Y30BH, and Y35 for Ferrite magnet is good.4) ... . We are RoHS certified. 5) Use of magnetOur magnets are used for motor speaker, hardware, package, cabinet lock ,door lock ...