1.Materials: Neodymium-Iron-Boron 2.Shape:ring,circle,disc,block 3.Certificate:ISO9001:2000,SGS,CTI... Magnet(NdFeB magnet) ... Zn, Epoxy, Gold, and etc.Sizes: according to your requirementsShapes: disc, cylinder, sphere, block ,ring ,tile, arc, and etc.High magnetic ... are widely used in computers(voice coil motor of hard disc drive, pick-up of optical disk drive), mobile phones, wind ...