Concave hole tegular NdFeB magnet 1,Powerful gravitation 2,Never demagnetization 3.Antirust 4.High work temperature Jesu Noah Magnet company devote to special ... Dy),Holmium(Ho) and Terbium(Tb) . 2,Quality of our magnet every products of our's will be checked 5 process ... to control the quality .3,the main use of our magnet Motor,IT industry ,acoustics ,Automotive,wind power ,comunication equipments ...