... to make it strong. General features:Grades:N33,N35,N38,N40,N42,N45,N48,N50,N52, (M, H, SH, EH ... Sizes: according to your requirementsShapes: disc, cylinder, sphere, block ,ring ,tile, arc, and etc.High magnetic performance (Br: 11,000 to ... optical disk drive), mobile phones, wind generator, magnetic resonance image, Hi-Fi system, auto motors, etc. Certifications:ISO9001:2000SGSCTI NdFeB Magnetic disk