Neodymium-iron-boron magnet is one kind of the permanent magnets.
Material Grade of NdFeB magnets:
Magnet N-( N35, N38, N40, N42, N45, N48, N50),
Magnet M-(35M, 38M, 40M, 42M, 45M, 48M),
Magnet H-(35H, 38H, 40H, 42H, 45H),
Magnet SH-(30SH, 33SH, 35SH, 38SH, 40SH, 42SH),
Magnet UH-( 28UH, 30UH, 33UH, 35UH, 38UH),
Magnet EH-(28EH, 30EH, 30EH, 33EH, 35EH)